docs(contributing): change instructions for vim, reference gnols (gno…

…lang#1113)

Setting syntax=go instead of filetype=go allows us to have syntax
highlighting without triggering vim-go. Also added a reference to
@jdkato's great [gnols](https://github.com/jdkato/gnols)

---------

Co-authored-by: Manfred Touron <94029+moul@users.noreply.github.com>

CONTRIBUTING.md

@@ -79,14 +79,15 @@ Add to your `.vimrc` file:
 
 ```vim
 function! GnoFmt()
-    cexpr system('gofmt -e -w ' . expand('%')) "or replace with gofumpt, see below
-    edit!
+	cexpr system('gofmt -e -w ' . expand('%')) " or replace with gofumpt, see below
+	edit!
+	set syntax=go
 endfunction
 command! GnoFmt call GnoFmt()
 augroup gno_autocmd
-    autocmd!
-    autocmd BufNewFile,BufRead *.gno set filetype=go
-    autocmd BufWritePost *.gno GnoFmt
+	autocmd!
+	autocmd BufNewFile,BufRead *.gno set syntax=go
+	autocmd BufWritePost *.gno GnoFmt
 augroup END
 ```
 
@@ -96,6 +97,9 @@ To use *gofumpt* instead of *gofmt*, as hinted in the comment, you may either ha
 cexpr system('go run -modfile </path/to/gno>/misc/devdeps/go.mod mvdan.cc/gofumpt -w ' . expand('%'))
 ```
 
+There is an experimental and unofficial [Gno Language Server](https://github.com/jdkato/gnols)
+developed by the community, with an installation guide for Neovim.
+
 #### Emacs Support
 
 1. Install [go-mode.el](https://github.com/dominikh/go-mode.el).
@@ -105,6 +109,11 @@ cexpr system('go run -modfile </path/to/gno>/misc/devdeps/go.mod mvdan.cc/gofump
 (add-to-list 'auto-mode-alist '("\\.gno\\'" . go-mode))
 ```
 
+#### Sublime Text
+
+There is an experimental and unofficial [Gno Language Server](https://github.com/jdkato/gnols)
+developed by the community, with an installation guide for Sublime Text.
+
 ### Local Setup
 
 To get started with Gno development, the process is relatively straightforward.