put the whole repo inside Docker

README.md

@@ -220,4 +220,4 @@ server {
 
 For legal reasons, the source of Taiko Web would be no longer provided on GitHub or other public Git platforms. But it's available inside this Docker image at `/usr/src/app` with the entire git history. Apology that this would make the repo become large.
 
-Please use
+Please use `docker cp` to grab the source from this image.