Gitea with first upper case + typos (#30739) (#30747)

Backport #30739 by @mainboarder

* Corrected gitea to Gitea
* fixed some typos

Co-authored-by: mainboarder <git@mainboarder.de>

docs/content/usage/repo-mirror.en-us.md

 
 To set up a mirror from Gitea to GitHub, you need to follow these steps:
 
-1. Create a [GitHub personal access token](https://docs.github.com/en/github/authenticating-to-github/creating-a-personal-access-token) with the *public_repo* box checked. Also check the **workflow** checkbox in case your repo using act for continuous integration.
+1. Create a [GitHub personal access token](https://docs.github.com/en/github/authenticating-to-github/creating-a-personal-access-token) with the *public_repo* box checked. Also check the **workflow** checkbox in case your repo uses GitHub Actions for continuous integration.
 2. Create a repository with that name on GitHub. Unlike Gitea, GitHub does not support creating repositories by pushing to the remote. You can also use an existing remote repo if it has the same commit history as your Gitea repo.
 3. In the settings of your Gitea repo, fill in the **Git Remote Repository URL**: `https://github.com/<your_github_group>/<your_github_project>.git`.
 4. Fill in the **Authorization** fields with your GitHub username and the personal access token as **Password**.
 
 ### Mirror an existing ssh repository
 
-Currently gitea supports no ssh push mirrors. You can work around this by adding a `post-receive` hook to your gitea repository that pushes manually.
+Currently Gitea supports no ssh push mirrors. You can work around this by adding a `post-receive` hook to your Gitea repository that pushes manually.
 
-1. Make sure the user running gitea has access to the git repo you are trying to mirror to from shell.
-2. On the Webinterface at the repository settings > git hooks add a post-receive hook for the mirror. I.e.
+1. Make sure the user running Gitea has access to the git repo you are trying to mirror to from shell.
+2. On the web interface at the repository settings > git hooks add a post-receive hook for the mirror. I.e.
 
 ```
 #!/usr/bin/env bash