implement some of the trivial backend plugins

Signed-off-by: Fredrik Adelöw <freben@gmail.com>

plugins/proxy-backend/package.json

@@ -8,7 +8,8 @@
   "publishConfig": {
     "access": "public",
     "main": "dist/index.cjs.js",
-    "types": "dist/index.d.ts"
+    "types": "dist/index.d.ts",
+    "alphaTypes": "dist/index.alpha.d.ts"
   },
   "backstage": {
     "role": "backend-plugin"
@@ -24,7 +25,7 @@
   ],
   "scripts": {
     "start": "backstage-cli package start",
-    "build": "backstage-cli package build",
+    "build": "backstage-cli package build --experimental-type-build",
     "lint": "backstage-cli package lint",
     "test": "backstage-cli package test",
     "prepack": "backstage-cli package prepack",
@@ -33,6 +34,7 @@
   },
   "dependencies": {
     "@backstage/backend-common": "workspace:^",
+    "@backstage/backend-plugin-api": "workspace:^",
     "@backstage/config": "workspace:^",
     "@types/express": "^4.17.6",
     "express": "^4.17.1",
@@ -56,7 +58,8 @@
   },
   "files": [
     "dist",
-    "config.d.ts"
+    "config.d.ts",
+    "alpha"
   ],
   "configSchema": "config.d.ts"
 }