Push option bonus for PTC docs (#23473)

Follow-up for #23458 

I could have suggested this on the original PR, but I thought there
would be more to add. Hadn't noticed the push options docs already had
nearly the same shell command. 😅

Signed-off-by: jolheiser <john.olheiser@gmail.com>

Author: jolheiser

docs/content/doc/usage/push-options.en-us.md

@@ -29,5 +29,5 @@ were added.
 Example of changing a repository's visibility to public:
 
 ```shell
-git push -o repo.private=false -u origin master
+git push -o repo.private=false -u origin main
 ```

docs/content/doc/usage/push-options.zh-tw.md

@@ -29,5 +29,5 @@ Gitea 從 `1.13` 版開始支援某些 [push options](https://git-scm.com/docs/g
 以下範例修改儲存庫的可見性為公開：
 
 ```shell
-git push -o repo.private=false -u origin master
+git push -o repo.private=false -u origin main
 ```

docs/content/doc/usage/push-to-create.en-us.md

@@ -34,3 +34,7 @@ git push -u origin main
 ```
 
 This assumes you are using an SSH remote, but you can also use HTTPS remotes as well.
+
+## Push options (bonus)
+
+Push-to-create will default to the visibility defined by `DEFAULT_PUSH_CREATE_PRIVATE` in `app.ini`. To explicitly set the visibility, you can use a [push option]({{< relref "doc/usage/push-options.en-us.md" >}}).