Add TestFrontend documentation and UndoSystem buffer reference update.

- Document `TestFrontend` for programmatic testing, including examples and usage details.
- Add `UpdateBufferReference` to `UndoSystem` to support updating buffer associations.

.github/workflows/release.yml

@@ -0,0 +1,37 @@
+name: Release
+
+on:
+  push:
+    tags:
+      - 'v*'
+  workflow_dispatch: { }
+
+permissions:
+  contents: write
+
+jobs:
+  homebrew:
+    name: Bump Homebrew formula
+    # Skip this job in case of git pushes to prerelease tags
+    if: ${{ github.event_name != 'push' || !contains(github.ref, '-') }}
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    steps:
+      - name: Extract version
+        id: extract-version
+        run: |
+          echo "tag-name=${GITHUB_REF#refs/tags/}" >> $GITHUB_OUTPUT
+
+      - uses: mislav/bump-homebrew-formula-action@v3
+        with:
+          formula-name: kte
+          formula-path: Formula/kte.rb
+          homebrew-tap: kisom/homebrew-tap
+          base-branch: master
+          commit-message: |
+            {{formulaName}} {{version}}
+            
+            Created by https://github.com/mislav/bump-homebrew-formula-action
+        env:
+          COMMITTER_TOKEN: ${{ secrets.GH_CPAT }}