some fixes and improvements to build

- change .yarn/ gitignore to include subprojects
- add nodejs-rfb to build (and bump it)
- add clean script

package.json

@@ -20,6 +20,7 @@
 	"packageManager": "yarn@4.1.1",
 	"scripts": {
 		"build": "just",
-		"serve": "node cvmts/dist/index.js"
+		"serve": "node cvmts/dist/index.js",
+		"clean": "rm -rf .parcel-cache .yarn **/node_modules **/dist cvm-rs/target cvm-rs/index.node"
 	}
 }