Add maintenance workflows from main repo (edit PR description/clean u…

…p ready to merge label) (#406)

# References and relevant issues

Depends on napari/napari#6839

# Description

In the main repository, we have 2 useful workflows

1) Remove html comment In PR description
2) Remove "Ready to merge" 

This PR adds this to docs repository by calling these workflows. Calling
workflow instead of coping, it allows having fix in a single place.

---------

Co-authored-by: Peter Sobolewski <76622105+psobolewskiPhD@users.noreply.github.com>

.github/workflows/edit_pr_description.yml

@@ -0,0 +1,16 @@
+name: Remove html In PR description
+on:
+  # see https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#pull_request_target
+  pull_request_target:
+    types:
+      - opened
+      - synchronize
+      - reopened
+      - edited
+permissions:
+  pull-requests: write
+
+jobs:
+  remove_comment:
+    name: Remove html comments.
+    uses: napari/napari/.github/workflows/edit_pr_description.yml@main

.github/workflows/remove_ready_to_merge.yml

@@ -0,0 +1,15 @@
+name: Remove "ready to merge" label
+
+on:
+  pull_request_target:
+    types: [closed]
+  workflow_call:
+
+
+permissions:
+  pull-requests: write
+
+jobs:
+  remove_label:
+    name: Remove ready to merge label
+    uses: napari/napari/.github/workflows/remove_ready_to_merge.yml@main