adding .rockspec file to generate a luarocks rock

lain.rockspec

@@ -0,0 +1,22 @@
+package = "lain"
+version = "1.0.0"
+source = {
+   url = "https://github.com/copycat-killer/lain",
+   tag = "v.1.0.0"
+}
+description = {
+   summary = "A layoutm widget and utilities library for the Awesome Window Manager",
+   detailed = [[
+        Successor of awesome-vain, this module provides new layouts, a set of widgets and utility functions, in order to improve Awesome usability and configurability.
+    ]],
+   homepage = "https://github.com/copycat-killer/lain",
+   license = "GPL v2"
+}
+dependencies = {
+   "lua >= 5.1"
+}
+supported_platforms = { "linux" }
+build = {
+   type = "builtin",
+   modules = { lain = "init.lua" },
+}