home: create 'modules/home' folder

Consolidating all modules under the same path, to clear out the
top-level directory.

modules/home/vim/after/plugin/mappings/commentary.lua

@@ -0,0 +1,10 @@
+local wk = require("which-key")
+
+local keys = {
+    name = "Comment/uncomment",
+    c = "Current line",
+    u = "Uncomment the current and adjacent commented lines",
+    ["gc"] = "Uncomment the current and adjacent commented lines",
+}
+
+wk.register(keys, { prefix = "gc" })