Add documentation coverage.

.github/workflows/documentation-coverage.yaml

@@ -0,0 +1,25 @@
+name: Documentation Coverage
+
+on: [push, pull_request]
+
+permissions:
+  contents: read
+
+env:
+  CONSOLE_OUTPUT: XTerm
+  COVERAGE: PartialSummary
+
+jobs:
+  validate:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+    - uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: "3.3"
+        bundler-cache: true
+
+    - name: Validate coverage
+      timeout-minutes: 5
+      run: bundle exec bake decode:index:coverage lib

.github/workflows/coverage.yaml → .github/workflows/test-coverage.yaml

@@ -1,4 +1,4 @@
-name: Coverage
+name: Test Coverage
 
 on: [push, pull_request]
 

gems.rb

@@ -18,6 +18,7 @@
 group :test do
 	gem "covered"
 	gem "sus"
+	gem "decode"
 
 	gem "bake-test"
 	gem "bake-test-external"