Added presser/builtins

Module is responsible for implementing a lazy-loader for any new tool
which is defined in table@modules. This function makes use of a
lazy-loading strategy (needs citation).

presser/builtins/init.lua

@@ -0,0 +1,16 @@
+local builtins = {}
+
+local function require_on_exported_call (require_path)
+  return setmetatable({}, {
+    __index = function(_, k)
+      return function(...)
+        return require(require_path)[k](...)
+      end
+    end,
+  })
+end
+
+
+builtins.find_replace = require_on_exported_call("presser.builtins.__modules").find_replace
+
+return builtins