chore: add release-please workflow for automated versioning

- Add .github/workflows/release-please.yml pinned to exact SHA
- Add release-please-config.json for node package type
- Add .release-please-manifest.json seeded at current version 0.3.0
- Uses PAT secret RELEASE_PLEASE_TOKEN to allow workflow triggering

Closes #3

Author: MattDevy

.github/workflows/release-please.yml

@@ -0,0 +1,21 @@
+name: Release Please
+
+on:
+  push:
+    branches:
+      - main
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  release-please:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: googleapis/release-please-action@16a9c90856f42705d54a6fda1823352bdc62cf38 # v4.4.0
+        id: release
+        with:
+          token: ${{ secrets.RELEASE_PLEASE_TOKEN }}
+          config-file: release-please-config.json
+          manifest-file: .release-please-manifest.json

.release-please-manifest.json

@@ -0,0 +1,3 @@
+{
+  ".": "0.3.0"
+}

release-please-config.json

@@ -0,0 +1,7 @@
+{
+  "$schema": "https://raw.githubusercontent.com/googleapis/release-please/main/schemas/config.json",
+  "release-type": "node",
+  "packages": {
+    ".": {}
+  }
+}