refactor: fix config type annotations

doc/gopher.nvim.txt

@@ -44,12 +44,6 @@ to install them synchronously pass `{sync = true}` as an argument.
 
 
 ==============================================================================
-------------------------------------------------------------------------------
-                                                                        *config*
-                                    `config`
-Type ~
-`(gopher.Config)`
-
 ------------------------------------------------------------------------------
                                                             *gopher.nvim-config*
                                 `default_config`

lua/gopher/config.lua

@@ -1,3 +1,6 @@
+---@type gopher.Config
+---@dochide
+---@diagnostic disable-next-line: missing-fields .setup() gets injected later
 local config = {}
 
 ---@tag gopher.nvim-config.ConfigGoTagTransform
@@ -16,6 +19,7 @@ local config = {}
 ---@tag gopher.nvim-config
 ---@eval return MiniDoc.afterlines_to_code(MiniDoc.current.eval_section)
 ---@class gopher.Config
+---@field setup fun(user_config?: gopher.Config)
 local default_config = {
   -- log level, you might consider using DEBUG or TRACE for debugging the plugin
   ---@type number
@@ -112,5 +116,4 @@ setmetatable(config, {
 })
 
 ---@dochide
----@return gopher.Config
-return config --[[ @as gopher.Config ]]
+return config

spec/unit/config_test.lua

@@ -7,11 +7,14 @@ config["can be called without any arguments passed"] = function()
 end
 
 config["can be called with empty table"] = function()
+  ---@diagnostic disable-next-line: missing-fields
   require("gopher").setup {}
 end
 
 config["should change option"] = function()
   local log_level = 1234567890
+
+  ---@diagnostic disable-next-line: missing-fields
   require("gopher").setup {
     log_level = log_level,
   }