Add sync-labels workflow

Author: ErikSchierboom

building/config.json

@@ -673,6 +673,12 @@
     "path": "building/tracks/ci/workflows/configlet.md",
     "title": "configlet workflow"
   },
+  {
+    "uuid": "fd512058-4525-4e14-a912-9df870025989",
+    "slug": "tracks/ci/workflows/sync-labels",
+    "path": "building/tracks/ci/workflows/sync-labels.md",
+    "title": "Sync labels workflow"
+  },
   {
     "uuid": "191b0fa1-96e2-48a6-ad2e-c34f57443799",
     "slug": "tracks/ci/migrating-from-travis",

building/tracks/ci/workflows.md

@@ -23,7 +23,7 @@ You should thus not manually change their contents.
 
 ### General workflows
 
-- `sync-labels.yml`: automatically syncs the repository's labels from a `labels.yml` file
+- [`sync-labels.yml`](/docs/building/tracks/ci/workflows/sync-labels): automatically syncs the repository's labels from a `labels.yml` file
 
 ### Track-specific workflows
 

building/tracks/ci/workflows/sync-labels.md

@@ -0,0 +1,21 @@
+# Sync labels workflow
+
+The sync labels workflow is defined in the `.github/workflows/sync-labels.yml` file.
+The goal of this workflow is to add/update/delete the repository's [GitHub labels](https://docs.github.com/en/issues/using-labels-and-milestones-to-track-work/managing-labels).
+The labels themselves are defined in the `.github/labels.yml` file.
+Whenever the `.github/labels.yml` file changes, the sync labels workflow will automatically update the repository's labels.
+
+## Customizing labels
+
+The labels defined in `.github/labels.yml` come in two forms:
+
+- Shared labels: these are labels used by _all_ Exercism repositories, and they're defined in the [org-wide-files repo](https://github.com/exercism/org-wide-files/blob/main/global-files/.github/labels.yml)
+- Track-specific labels: these are defined in an `.appends/.github/labels.yml` file
+
+To add track-specific labels, you'll need to add them to the `.appends/.github/labels.yml` file (see [this example](https://github.com/exercism/python/blob/main/.appends/.github/labels.yml)).
+Once you've merged the changes to `main`, a pull request will automatically be opened to change the `.github/labels.yml` file.
+After merging that PR, the labels will be automatically updated (see description above).
+
+```exercism/caution
+Never manually edit the `.github/labels.yml` file, as those changes will be overwritten the next time labels are synced.
+```