Get simple rg example to work

lua/telescope/builtin.lua

@@ -0,0 +1,31 @@
+--[[
+A collection of builtin pipelines for telesceope.
+
+Meant for both example and for easy startup.
+--]]
+
+local Finder = require('telescope.finder')
+local pickers = require('telescope.pickers')
+
+local builtin = {}
+
+builtin.rg_vimgrep = setmetatable({}, {
+  __call = function(t, ...)
+    -- builtin.rg_vimgrep("--type lua function")
+    print(t, ...)
+  end
+})
+
+builtin.rg_vimgrep.finder = Finder:new {
+  fn_command = function(prompt)
+    return string.format('rg --vimgrep %s', prompt)
+  end,
+
+  responsive = false
+}
+
+builtin.rg_vimgrep.picker = pickers.new {
+}
+
+
+return builtin