fix: add build scripts for homepage (codesandbox#2215)

Author: jyash97

package.json

@@ -21,7 +21,8 @@
     "start:vscode": "cross-env VSCODE=1 yarn start:fast & cd standalone-packages/monaco-editor && yarn simpleserver & cd standalone-packages/vscode && yarn watch",
     "start:dynamic": "lerna run dev --scope dynamic-pages --stream",
     "start:common": "lerna run start --scope common --stream",
-    "start:home": "cd packages/homepage && yarn start",
+    "start:home": "yarn build:deps && yarn start:home:fast",
+    "start:home:fast": "cd packages/homepage && yarn start",
     "start:test": "lerna run start:test --scope app --stream",
     "start:dev_api": "lerna run start:dev_api --scope app --stream",
     "test": "lerna run test --ignore codesandbox-browserfs",