URL in documentation points to the old Dockerfile

[Verhoeckx]

The url in README.md that points to the Dockfile, points to an old version of it.

The url is
https://github.com/gitpod-io/openvscode-releases/blob/eb59ab37e23f8d17532b4af4de37eafaf48037a5/Dockerfile#L64

And should be (IMHO)
https://github.com/gitpod-io/openvscode-releases/blob/main/Dockerfile

[jeanp413]

Thanks, updated the link 👍