Move GHA conditional into new guide.

Author: danielballan

.github/workflows/ci_tests_run_notebooks.yml

@@ -17,9 +17,6 @@ concurrency:
 
 jobs:
   tests:
-    # Do not run the test matrix on PRs affecting the rendering
-    if: ${{ !(github.event_name == 'pull_request') || !contains(github.event.pull_request.labels.*.name, 'html rendering / skip testing') }}
-
     name: ${{ matrix.os }} ${{ matrix.name }}
     runs-on: ${{ matrix.os }}
     strategy:
@@ -57,9 +54,6 @@ jobs:
 
 
   gha_buildhtml:
-    # When label is used, we do run buildhtml on GHA to check if the publishing job will run or not.
-    # Use in case when new content has run into troubles on CircleCI.
-    if: ${{ (github.event_name == 'pull_request') && contains(github.event.pull_request.labels.*.name, 'GHA buildhtml') }}
     name: Buildhtml testing
     runs-on: ubuntu-latest
     steps:

contributing.md

@@ -1,4 +1,6 @@
-# Guide to Contributing
+# Guide for Contributors
+
+This guide is for contributing content to the tutorials.
 
 First, clone this repository.
 

index.md

@@ -5,4 +5,5 @@
 :glob:
 tutorials/**/*
 contributing
+maintainers
 ```

maintainers.md

@@ -0,0 +1,16 @@
+# Guide for Maintainers
+
+This guide for configuring and maintaining collection of executable
+tutorials.
+
+## Specialized Patterns
+
+Sometimes it is convenient to disable a job in a GitHub Action on certain Pull
+Requests.  This may be added to the job to configure it to skip Pull Requests
+that have a given label called `LABEL`.
+
+```yaml
+jobs:
+  tests:
+    if: ${{ !(github.event_name == 'pull_request') || !contains(github.event.pull_request.labels.*.name, 'LABEL') }}
+```