move extension npm package files & add release automation

Signed-off-by: Jari Kolehmainen <jari.kolehmainen@gmail.com>

packages/extensions/.gitignore

@@ -0,0 +1,2 @@
+dist/
+__mocks__/

packages/extensions/package.json

@@ -0,0 +1,31 @@
+{
+  "name": "@k8slens/extensions",
+  "productName": "OpenLens extensions",
+  "description": "OpenLens - Open Source Kubernetes IDE: extensions",
+  "version": "6.3.0-alpha.0",
+  "copyright": "© 2022 OpenLens Authors",
+  "license": "MIT",
+  "main": "dist/src/extensions/extension-api.js",
+  "types": "dist/src/extensions/extension-api.d.ts",
+  "files": [
+    "dist/**/*.ts",
+    "__mocks__/*.ts",
+    "dist/**/*.js"
+  ],
+  "author": {
+    "name": "OpenLens Authors"
+  },
+  "dependencies": {
+    "@material-ui/core": "^4.12.3",
+    "@types/node": "^16.11.58",
+    "@types/react": "^17.0.45",
+    "@types/react-dom": "^17.0.16",
+    "@types/react-router": "^5.1.18",
+    "@types/react-router-dom": "^5.3.3",
+    "conf": "^7.0.1",
+    "mobx": "^6.5.0",
+    "mobx-react": "^7.3.0",
+    "react-select": "^5.3.2",
+    "typed-emitter": "^1.3.1"
+  }
+}