Upgrade to GitHub-native Dependabot

.github/dependabot.yml

@@ -0,0 +1,35 @@
+version: 2
+updates:
+- package-ecosystem: npm
+  directory: "/standalone"
+  schedule:
+    interval: monthly
+  open-pull-requests-limit: 10
+  target-branch: dependabot_prs
+  ignore:
+  - dependency-name: typescript
+    versions:
+    - 4.1.3
+  - dependency-name: "@types/node-fetch"
+    versions:
+    - 2.5.7
+- package-ecosystem: npm
+  directory: "/vscode"
+  schedule:
+    interval: monthly
+  open-pull-requests-limit: 10
+  target-branch: dependabot_prs
+  ignore:
+  - dependency-name: vsce
+    versions:
+    - 1.83.0
+    - 1.84.0
+  - dependency-name: typescript
+    versions:
+    - 4.1.3
+  - dependency-name: "@types/mocha"
+    versions:
+    - 8.2.0
+  - dependency-name: mocha
+    versions:
+    - 8.2.1