Add tests for Theatre.js + popular setups in the ecosystem (#165)

This implements some basic infra for testing Theatre.js with popular setups such as npm/yarn/pnpm, webpack/vite/parcel, js/ts, etc.

So far, the only existing setup has been with create-react-app. Will add more in the future.

Co-authored-by: Fülöp <fulopkovacs@users.noreply.github.com>
Co-authored-by: Aria Minaei <aria.minaei@gmail.com>

packages/browser-bundles/package.json

@@ -16,8 +16,10 @@
     "dist/**/*"
   ],
   "scripts": {
-    "build": "node -r esbuild-register ./devEnv/build.ts",
-    "prepublish": "node ../../devEnv/ensurePublishing.js"
+    "build": "yarn run build:js",
+    "build:js": "node -r esbuild-register ./devEnv/build.ts",
+    "prepublish": "node ../../devEnv/ensurePublishing.js",
+    "clean": "rm -rf ./dist && rm -f tsconfig.tsbuildinfo"
   },
   "devDependencies": {
     "esbuild": "^0.12.15",