readme: fix a typo

README.md

@@ -7,7 +7,7 @@ The API is based off of the 8.13.0 API and will likely aggressively track new
 API additions, so the newest release may not support talking to older releases
 where fields have been added..
 
-All API types should be implemnted in the [types](src/types.rs.in) module.
+All API types should be implemented in the [types](src/types.rs.in) module.
 These types should generally be implemented based on the `lib/api/entities.rb`
 module in the Gitlab repository. However, in the interest of usability,
 entities may be combined using `Option` to handle the differences. Generally,