chore: add dev dependencies for cloud-rad ref docs (#772)

Author: fhinkel

package.json

@@ -42,7 +42,9 @@
     "pretest": "npm run compile",
     "test": "c8 mocha build/test",
     "clean": "gts clean",
-    "precompile": "gts clean"
+    "precompile": "gts clean",
+    "api-extractor": "api-extractor run --local",
+    "api-documenter": "api-documenter yaml --input-folder=temp"
   },
   "dependencies": {
     "@google-cloud/paginator": "^3.0.0",
@@ -92,7 +94,9 @@
     "typescript": "^3.8.3",
     "uuid": "^8.0.0",
     "webpack": "^4.42.0",
-    "webpack-cli": "^3.3.11"
+    "webpack-cli": "^3.3.11",
+    "@microsoft/api-documenter": "^7.8.10",
+    "@microsoft/api-extractor": "^7.8.10"
   },
   "engines": {
     "node": ">=10"