Correct a language error in reverse proxy doc (#9455)

* Correct a language error in reverse proxy doc

* Apply suggestions from code review

Co-Authored-By: zeripath <art27@cantab.net>

Co-authored-by: zeripath <art27@cantab.net>

docs/content/doc/usage/reverse-proxies.en-us.md

@@ -14,7 +14,7 @@ menu:
 ---
 
 ##  Using Nginx as a reverse proxy
-If you want Nginx to serve your Gitea instance, you can the following `server` section inside the `http` section of `nginx.conf`:
+If you want Nginx to serve your Gitea instance, add the following `server` section to the `http` section of `nginx.conf`:
 
 ```
 server {