refactor: minimize amount of vimscript (#96)

* refactor: remove autoload

* since nvim 0.9 health.lua files are threaded as checkhealth provider

*  prof of concept 

* fix(runner.gocmd)!: i forgot to update it when i was working on #85

* fix(plugin): now commands register properly

* fix(plugin): fix command name for :GoIfErr

* fix(plugin): respect `setup_commands` option

* docs: update

* refactor(plugin): use vim.schedule

* docs: update CONTRIBUTING

lua/gopher/init.lua

@@ -55,19 +55,19 @@ gopher.test = {
 }
 
 gopher.get = function(...)
-  gocmd("get", { ... })
+  gocmd("get", ...)
 end
 
 gopher.mod = function(...)
-  gocmd("mod", { ... })
+  gocmd("mod", ...)
 end
 
 gopher.generate = function(...)
-  gocmd("generate", { ... })
+  gocmd("generate", ...)
 end
 
 gopher.work = function(...)
-  gocmd("work", { ... })
+  gocmd("work", ...)
 end
 
 return gopher