Restructure and move Git content (#18336)

* Rename map topic

* Delete map topic

* Rename map topic

* Add redirect

* Remove last two map topics

* Move article on adding a remote into a long-form guide

* Move article on changing a remote's URL

* Move articles on renaming and removing remotes

* Move remote URL article

* Fix typo

* Remove category index file

* Move a few articles to the new category

* Move a few more files

* Move managing remote repos article

* Move the rest of the getting started with git map topic

* Move the first half of the using git map topic

* Move the rest of the articles and 🔥 the directory

* Fix failing test

* Remove Using Git from product index

* Apply suggestions from code review

Co-authored-by: Laura Coursen <lecoursen@github.com>

* Apply suggestions from code review

Co-authored-by: Laura Coursen <lecoursen@github.com>

content/github/setting-up-and-managing-your-github-user-account/changing-your-github-username.md

@@ -32,7 +32,7 @@ After you change your username, {% data variables.product.product_name %} will a
 - Web links to your existing repositories will continue to work. This can take a few minutes to complete after you make the change.
 - Command line pushes from your local repository clones to the old remote tracking URLs will continue to work.
 
-If the new owner of your old username creates a repository with the same name as your repository, that will override the redirect entry and your redirect will stop working. Because of this possibility, we recommend you update all existing remote repository URLs after changing your username. For more information, see "[Changing a remote's URL](/articles/changing-a-remote-s-url)."
+If the new owner of your old username creates a repository with the same name as your repository, that will override the redirect entry and your redirect will stop working. Because of this possibility, we recommend you update all existing remote repository URLs after changing your username. For more information, see "[Managing remote repositories](/github/getting-started-with-github/managing-remote-repositories)."
 
 ### Links to your previous profile page
 
@@ -58,6 +58,5 @@ After changing your username, links to your previous profile page, such as `http
 
 ### Further reading
 
-- "[Changing a remote's URL](/articles/changing-a-remote-s-url)"
 - "[Why are my commits linked to the wrong user?](/articles/why-are-my-commits-linked-to-the-wrong-user)"{% if currentVersion == "free-pro-team@latest" %}
 - "[{% data variables.product.prodname_dotcom %} Username Policy](/articles/github-username-policy)"{% endif %}

content/github/setting-up-and-managing-your-github-user-account/merging-multiple-user-accounts.md

@@ -18,7 +18,7 @@ topics:
 {% endtip %}
 
 1. [Transfer any repositories](/articles/how-to-transfer-a-repository) from the account you want to delete to the account you want to keep. Issues, pull requests, and wikis are transferred as well. Verify the repositories exist on the account you want to keep.
-2. [Update the remote URLs](/articles/changing-a-remote-s-url) in any local clones of the repositories that were moved.
+2. [Update the remote URLs](/github/getting-started-with-github/managing-remote-repositories) in any local clones of the repositories that were moved.
 3. [Delete the account](/articles/deleting-your-user-account) you no longer want to use.
 
 ### Further reading

content/github/setting-up-and-managing-your-github-user-account/remembering-your-github-username-or-email.md

@@ -36,7 +36,7 @@ topics:
 
 ### Finding your username in your `user.name` configuration
 
-During set up, you may have [set your username in Git](/articles/setting-your-username-in-git). If so, you can review the value of this configuration setting:
+During set up, you may have [set your username in Git](/github/getting-started-with-github/setting-your-username-in-git). If so, you can review the value of this configuration setting:
 
 ```shell
 $ git config user.name