ci: modernize GitHub workflows and templates

Update CI workflow: restrict triggers to master+PRs, add concurrency
groups and npm cache. Update release-please and stale workflows to
latest action versions. Replace single ISSUE_TEMPLATE.md with YAML-
based templates (bug report, feature request, config). Rewrite
CONTRIBUTING.md for awesome-cordova-plugins.

.github/workflows/nodejs.yml

@@ -1,21 +1,27 @@
-name: Node CI
+name: CI
 
-on: [push]
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+
+concurrency:
+  group: ci-${{ github.ref }}
+  cancel-in-progress: true
 
 jobs:
   build:
     runs-on: ubuntu-latest
 
-    strategy:
-      matrix:
-        node-version: [20.x]
-
     steps:
-      - uses: actions/checkout@v4.2.2
-      - name: Use Node.js ${{ matrix.node-version }}
+      - uses: actions/checkout@v4.3.1
+
+      - name: Setup Node.js
         uses: actions/setup-node@v4.4.0
         with:
-          node-version: ${{ matrix.node-version }}
+          node-version: 22
+          cache: npm
 
       - name: Install dependencies
         run: npm ci
@@ -23,11 +29,8 @@ jobs:
       - name: Lint
         run: npm run lint -- --quiet
 
+      - name: Test
+        run: npm test
+
       - name: Build
         run: npm run build
-
-      - name: Test
-        run: npm run test
-
-      - name: Readmes
-        run: npm run readmes