GH Actions: auto-label new PRs

Turns out the PR template does not allow for frontmatter which would set a label on new PRs.

As I'd prefer all new (non-draft) PRs to be marked with `Status: triage`, I went looking for an action which could do this and ended up with an action which can do a lot more.

Again, let's give it a try and see how it goes.

Ref: https://github.com/srvaroa/labeler

.github/labeler.yml

@@ -0,0 +1,84 @@
+version: 1
+appendOnly: true
+labels:
+- label: "Status: triage"
+  draft: False
+  author-can-merge: False
+
+- label: "Core Component: Config & Ruleset & CLI options"
+  draft: False
+  files:
+  - "src/Config.php$"
+- label: "Core Component: Config & Ruleset & CLI options"
+  draft: False
+  files:
+  - "src/Ruleset.php$"
+- label: "Core Component: File"
+  draft: False
+  files:
+  - "src/Files/.*"
+- label: "Core Component: Fixer"
+  draft: False
+  files:
+  - "src/Fixer.php$"
+- label: "Core Component: Reports"
+  draft: False
+  files:
+  - "src/Reports/.*"
+- label: "Core Component: Tokenizer"
+  draft: False
+  files:
+  - "src/Tokenizers/.*"
+- label: "Core Component: Utils"
+  draft: False
+  files:
+  - "src/Util/.*"
+
+- label: "Focus: Comments/Docblocks"
+  draft: False
+  files:
+  - "src/Standards/.*/Sniffs/Commenting/"
+- label: "Focus: Fixer Conflicts"
+  draft: False
+  body: ".* fixer conflict.*"
+
+- label: "Standard: Generic"
+  draft: False
+  files:
+  - "src/Standards/Generic/.*"
+- label: "Standard: MySource"
+  draft: False
+  files:
+  - "src/Standards/MySource/.*"
+- label: "Standard: PEAR"
+  draft: False
+  files:
+  - "src/Standards/PEAR/.*"
+- label: "Standard: PSR1"
+  draft: False
+  files:
+  - "src/Standards/PSR1/.*"
+- label: "Standard: PSR2"
+  draft: False
+  files:
+  - "src/Standards/PSR2/.*"
+- label: "Standard: PSR12"
+  draft: False
+  files:
+  - "src/Standards/PSR12/.*"
+- label: "Standard: Squiz"
+  draft: False
+  files:
+  - "src/Standards/Squiz/.*"
+- label: "Standard: Zend"
+  draft: False
+  files:
+  - "src/Standards/Zend/.*"
+
+- label: "Type: bug"
+  draft: False
+  body: ".* bug .*"
+- label: "Type: documentation"
+  draft: False
+  files:
+  - "/Docs/[A-Za-z0-9-]*/.*Standard.xml$"

.github/pull_request_template.md

@@ -1,7 +1,3 @@
----
-labels: ['Status: triage']
----
-
 <!-- Provide a general summary of your changes in the title above. -->
 
 <!--

.github/workflows/label-new-prs.yml

@@ -0,0 +1,16 @@
+name: Label new PRs
+
+on:
+  # https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#pull_request_target
+  pull_request_target:
+    types:
+      - unlabeled
+
+jobs:
+  label-new-prs:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: srvaroa/labeler@master
+      env:
+        GITHUB_TOKEN: "${{ secrets.GITHUB_TOKEN }}"