lsp-scala is deprecated

[JesusMtnez]

Since emacs-lsp/lsp-mode#871 is merged, this repository is deprecated.

• Update README to explain it has been integrated in lsp-mode Deprecate lsp-scala #29
• Archive project
• Update metals/emacs documentation: Update emacs docs as scala is supported by lsp-mode directly now scalameta/metals#741

[kurnevsky]

Also perhaps it should be removed from melpa?
https://github.com/melpa/melpa/blob/master/recipes/lsp-scala

[rossabaker]

Is there an standard way to deprecate packages, so if someone has lsp-scala in their config, it steers points them to the right thing? I found obsolete functions, but I'm not sure that's right.

[rossabaker]

I'll archive the project as soon as we've confirmed we don't need to do more to do a graceful wind down in MELPA.