[Fix sorin-ionescu#100] Add documentation for completion

modules/completion/README.md

@@ -0,0 +1,21 @@
+Completion
+==========
+
+Loads and configures tab completion and provides additional completions from the
+[zsh-completions][1] project.
+
+Contributors
+------------
+
+Completions should be submitted to the [zsh-completions][1] project according to its
+rules and regulations. This module will be synched against it.
+
+Authors
+-------
+
+*The authors of this module should be contacted via the GitHub issue tracker.*
+
+ - [Sorin Ionescu](/sorin-ionescu)
+
+[1]: /zsh-users/zsh-completions
+