escape special chars before search so we can grep [(...)]

lua/fzf-lua/providers/grep.lua

@@ -46,6 +46,10 @@ M.grep = function(opts)
     "rg_opts", "grep_opts",
   })
 
+  if opts.search and #opts.search>0 then
+    opts.search = utils.rg_escape(opts.search)
+  end
+
   if opts.repeat_last_search == true then
     opts.search = config.grep.last_search
   end
@@ -103,6 +107,10 @@ M.live_grep = function(opts)
     "rg_opts", "grep_opts",
   })
 
+  if opts.search and #opts.search>0 then
+    opts.search = utils.rg_escape(opts.search)
+  end
+
   -- resetting last_search will return
   -- {q} placeholder in our command
   opts.last_search = opts.search

lua/fzf-lua/utils.lua

@@ -48,6 +48,14 @@ function M.is_git_repo()
   return M._if(M.shell_error(), false, true)
 end
 
+function M.rg_escape(str)
+  --  [(~'"\/$?'`*&&||;[]<>)]
+  --  escape "\~$?*|[()"
+  return str:gsub("[\\~$?*|\\[()]", function(x)
+    return '\\' .. x
+  end)
+end
+
 M.read_file = function(filepath)
   local fd = vim.loop.fs_open(filepath, "r", 438)
   if fd == nil then return '' end