Implement source specific options

lua/cmp/types/cmp.lua

@@ -95,6 +95,9 @@ cmp.PreselectMode.None = 'none'
 ---@class cmp.SourceConfig
 ---@field public name string
 ---@field public opts table
+---@field public keyword_pattern string
+---@field public keyword_length number
+---@field public max_item_count number
 
 return cmp