#4 add README notes on updating + fix typo

Author: gingeleski

README.md

@@ -11,7 +11,7 @@ Execute the contents of [**libreveal.min.js**](https://github.com/gingeleski/lib
 
 See the unminified [**libreveal.js**](https://github.com/gingeleski/libreveal.js/blob/master/libreveal.js) script if you're curious how this works and/or what checks are run.
 
-## Support libraries
+## Supported libraries
 
 Currently this will detect...
 
@@ -39,6 +39,14 @@ Currently this will detect...
 - ExtJS
 - Bootstrap
 
+## Updating
+
+Run the Python script `compile.py` that's in `src/` to sync this with RetireJS.
+
+Integrate your own edits via the libreveal file in `src/json/`.
+
+There are no dependencies - just `cd` into `src/` and run `python compile.py` (note Python 3.x is needed though).
+
 ## Credit
 
 Derived in part from [**retire.js**](https://github.com/retirejs/retire.js/) identifiers - this stands on the shoulders of that project.