Change Go LS default to gopls

[ilohmar]

github.com/sourcegraph/go-langserver has been put on the backburner, and
the maintainers themselves advocate using Google's gopls instead. gopls
is actively developed and, although still labeled "alpha", already works
very nicely.

---

[joaotavora]

and the maintainers themselves advocate using Google's gopls instead

Can you include a reference to a source for this recommendation?

[ilohmar]

Right at the start of https://github.com/sourcegraph/go-langserver/blob/master/README.md:

Note: We have deprioritized work on this language server for use in editors in favor of Google's
Go language server, gopls. It is in the best interests of the community to only have a single
language server.

It is my interpretation, especially of the second sentence, that gopls is the way to go (and I agree, but that's beside the point, I guess).

[joaotavora]

Alright, do you have FSF papers signed? (also important for your other contribution...)

[ilohmar]

Oh, did you mean to include the reference in the commit message? Can surely do that as well...

[ilohmar]

Yeah, papers signed for Emacs years ago. Also, I already contributed recently :)

[joaotavora]

Oh, did you mean to include the reference in the commit message?

I didn't, but redoing the commit message in the format used by Eglot's other commits is useful. In this case it would be:

Use gols server as a default for Go (#304)

Developers recommend it: see 
https://github.com/sourcegraph/go-langserver/blob/master/README.md:

* eglot (eglot-server-programs): Use gols.

* README.md: mention gols instead of go-langserver.

[ilohmar]

Sure, I always forget that.. coming soon.

[ilohmar]

It's gopls, really ;)

[joaotavora]

Looks good.