Update linting workflows

- Remove deprecated misspell script.
- Consolidate linting into one workflow.
- Fix some markdownlint warnings.
- Add GitHub Actions linter.
- Pin markdown-link-check version.

Author: martincostello

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,11 +1,9 @@
-Fixes #
-
-## Changes
+# Changes
 
 Please provide a brief description of the changes here.
 
 ## Merge requirement checklist
 
 * [ ] Unit tests added/updated
-* [ ] [`CHANGELOG.md`](https://github.com/grafana/grafana-opentelemetry-dotnet) file updated for non-trivial changes
+* [ ] [`CHANGELOG.md`](https://github.com/grafana/grafana-opentelemetry-dotnet) updated
 * [ ] Changes in public API reviewed (if applicable)

.github/actionlint-matcher.json

@@ -0,0 +1,17 @@
+{
+  "problemMatcher": [
+    {
+      "owner": "actionlint",
+      "pattern": [
+        {
+          "regexp": "^(?:\\x1b\\[\\d+m)?(.+?)(?:\\x1b\\[\\d+m)*:(?:\\x1b\\[\\d+m)*(\\d+)(?:\\x1b\\[\\d+m)*:(?:\\x1b\\[\\d+m)*(\\d+)(?:\\x1b\\[\\d+m)*: (?:\\x1b\\[\\d+m)*(.+?)(?:\\x1b\\[\\d+m)* \\[(.+?)\\]$",
+          "file": 1,
+          "line": 2,
+          "column": 3,
+          "message": 4,
+          "code": 5
+        }
+      ]
+    }
+  ]
+}

.github/workflows/lint.yml

@@ -0,0 +1,52 @@
+name: lint
+
+on:
+  pull_request:
+    branches: [ main ]
+  workflow_dispatch:
+
+permissions: {}
+
+env:
+  FORCE_COLOR: 3
+  TERM: xterm
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+
+    steps:
+
+    - name: Checkout code
+      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      with:
+        filter: 'tree:0'
+        persist-credentials: false
+        show-progress: false
+
+    - name: Add actionlint problem matcher
+      run: echo "::add-matcher::.github/actionlint-matcher.json"
+
+    - name: Lint workflows
+      uses: docker://rhysd/actionlint:1.7.7@sha256:887a259a5a534f3c4f36cb02dca341673c6089431057242cdc931e9f133147e9
+      with:
+        args: -color
+
+    - name: Lint markdown
+      uses: DavidAnson/markdownlint-cli2-action@992badcdf24e3b8eb7e87ff9287fe931bcb00c6e # v20.0.0
+      with:
+        config: '.markdownlint.yaml'
+        globs: |
+          **/*.md
+
+    - name: Install markdown-link-check
+      env:
+        # renovate: datasource=npm depName=markdown-link-check packageName=markdown-link-check
+        MARKDOWN_LINK_CHECK_VERSION: 3.13.7
+      run: sudo npm install -g "markdown-link-check@${MARKDOWN_LINK_CHECK_VERSION}"
+
+    - name: Check markdown links
+      run: "find . -name '*.md' -print0 | xargs -0 -n1 markdown-link-check --config .markdown_link_check_config.json"