[Feature] Encapsulate config logic (#1338)

* Define core/builtins, streamline status_color interface

* Encapsulate configuration in its own module

* Add fallback to lv-config.lua

* Rectify settings loading order to allow overriding vim options

* Move default-config into config/ module

* replace uv.fs_stat with utils.is_file

lua/config/init.lua

@@ -0,0 +1,44 @@
+local M = {
+  path = string.format("%s/.config/lvim/config.lua", os.getenv "HOME"),
+}
+
+--- Initialize lvim default configuration
+-- Define lvim global variable
+function M:init()
+  local utils = require "utils"
+
+  require "config.defaults"
+
+  local builtins = require "core.builtins"
+  builtins.config(self)
+
+  local settings = require "config.settings"
+  settings.load_options()
+
+  -- Fallback config.lua to lv-config.lua
+  if not utils.is_file(self.path) then
+    local lv_config = self.path:gsub("config.lua$", "lv-config.lua")
+    print(self.path, "not found, falling back to", lv_config)
+
+    self.path = lv_config
+  end
+end
+
+--- Override the configuration with a user provided one
+-- @param config_path The path to the configuration overrides
+function M:load(config_path)
+  config_path = config_path or self.path
+  local ok, err = pcall(vim.cmd, "luafile " .. config_path)
+  if not ok then
+    print("Invalid configuration", config_path)
+    print(err)
+    return
+  end
+
+  self.path = config_path
+
+  local settings = require "config.settings"
+  settings.load_commands()
+end
+
+return M