Fix typo (#424)

* Fix typo and add clearer info

Fix typo and be more specific about where API endpoint can be accessed

* Update content/guides/09.extensions/2.api-extensions/2.endpoints.md

---------

Co-authored-by: ian <licitdev@gmail.com>

Author: seanmangar

content/guides/09.extensions/2.api-extensions/2.endpoints.md

@@ -25,7 +25,7 @@ Alternatively, you can export a configuration object to be able to customize the
 ```js
 export default {
 	id: 'greet',
-	handler: (router, countext) => {
+	handler: (router, context) => {
 		router.get('/', (req, res) => res.send('Hello, World!'));
 		router.get('/intro', (req, res) => res.send('Nice to meet you.'));
 		router.get('/goodbye', (req, res) => res.send('Goodbye!'));