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/getting-started-with-github/index.md

@@ -12,6 +12,9 @@ redirect_from:
   - /categories/53/articles/
   - /categories/setup/
   - /categories/getting-started-with-github
+  - /categories/19/articles/
+  - /categories/using-git
+  - /github/using-git
 versions:
   free-pro-team: '*'
   enterprise-server: '*'
@@ -68,7 +71,6 @@ topics:
     {% link_in_list /access-permissions-on-github %}    
     {% link_in_list /faq-about-changes-to-githubs-plans %}
 
-
 {% topic_link_in_list /signing-up-for-github %}
     {% link_in_list /signing-up-for-a-new-github-account %}
     {% link_in_list /verifying-your-email-address %}
@@ -89,4 +91,25 @@ topics:
     {% link_in_list /saving-repositories-with-stars %}
     {% link_in_list /following-people %}
 
+{% topic_link_in_list /getting-started-with-git %}
+    {% link_in_list /setting-your-username-in-git %}
+    {% link_in_list /caching-your-github-credentials-in-git %}
+    {% link_in_list /why-is-git-always-asking-for-my-password %}
+    {% link_in_list /updating-credentials-from-the-macos-keychain %}
+    {% link_in_list /git-workflows %}
+    {% link_in_list /about-remote-repositories %}
+    {% link_in_list /managing-remote-repositories %}
+    {% link_in_list /associating-text-editors-with-git %}
+    {% link_in_list /configuring-git-to-handle-line-endings %}
+    {% link_in_list /ignoring-files %}
+
+{% topic_link_in_list /using-git %}
+    {% link_in_list /pushing-commits-to-a-remote-repository %}
+    {% link_in_list /getting-changes-from-a-remote-repository %}
+    {% link_in_list /dealing-with-non-fast-forward-errors %}
+    {% link_in_list /splitting-a-subfolder-out-into-a-new-repository %}
+    {% link_in_list /about-git-subtree-merges %}
+    {% link_in_list /about-git-rebase %}
+    {% link_in_list /using-git-rebase-on-the-command-line %}
+    {% link_in_list /resolving-merge-conflicts-after-a-git-rebase %}
 </div>