Add git submodule for dev-env repository. (#12264)

To simplify every our dev's experience, this PR adds the repository with necessary configuration to a submodule, and adds proper symlinks so they will be automatically picked by vite.

The only step is initializing the submodule:
```
$ git submodule update --init
```

Anyone without permission to the dev-env repo will get `Permission denied` error to above command.

Additionally, removed the most jarringly wrong information from our CONTRIBUTING.md. This is not end of updating docs, however.

.github/workflows/bazel-build.yml

@@ -15,7 +15,7 @@ jobs:
         with:
           bazelisk-cache: true
           bazelrc: build --remote_cache=grpcs://${{ vars.ENSO_BAZEL_CACHE_URI }} --remote_cache_header="authorization=Basic ${{ secrets.ENSO_BAZEL_CACHE_TOKEN }}"
-      - uses: actions/checkout@v4
+      - uses: submodules
       - name: Expose env variables
         run: |
           cat << END > app/gui/.env.production

.github/workflows/changelog.yml

@@ -33,7 +33,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4

.github/workflows/engine-benchmark.yml

@@ -35,7 +35,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4

.github/workflows/engine-checks-nightly.yml

@@ -36,7 +36,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -87,7 +86,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -136,7 +134,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -186,7 +183,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -236,7 +232,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -286,7 +281,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -348,7 +342,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -408,7 +401,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -469,7 +461,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -530,7 +521,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -591,7 +581,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -656,7 +645,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -719,7 +707,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -783,7 +770,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -847,7 +833,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4

.github/workflows/engine-checks-optional.yml

@@ -38,7 +38,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -88,7 +87,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -149,7 +147,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4

.github/workflows/engine-checks.yml

@@ -38,7 +38,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -88,7 +87,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -138,7 +136,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -199,7 +196,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -260,7 +256,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - name: Build Script Setup
         run: ./run --help || (git clean -ffdx && ./run --help)
         env:
@@ -301,7 +296,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -365,7 +359,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -429,7 +422,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4

.github/workflows/extra-nightly-tests.yml

@@ -35,7 +35,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -107,7 +106,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4

.github/workflows/ide-packaging-optional.yml

@@ -38,7 +38,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -95,7 +94,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -158,7 +156,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4

.github/workflows/ide-packaging.yml

@@ -38,7 +38,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -105,7 +104,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -162,7 +160,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -228,7 +225,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -291,7 +287,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4
@@ -384,7 +379,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4

.github/workflows/promote.yml

@@ -57,7 +57,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           clean: false
-          submodules: recursive
       - if: runner.os == 'macOS'
         name: Setup nodejs version
         uses: actions/setup-node@v4