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/git-workflows.md

@@ -0,0 +1,13 @@
+---
+title: Git workflows
+intro: '{% data variables.product.prodname_dotcom %} flow is a lightweight, branch-based workflow that supports teams and projects that deploy regularly.'
+redirect_from:
+  - /articles/what-is-a-good-git-workflow/
+  - /articles/git-workflows
+  - /github/using-git/git-workflows
+versions:
+  free-pro-team: '*'
+  enterprise-server: '*'
+  github-ae: '*'
+---
+You can adopt the {% data variables.product.prodname_dotcom %} flow method to standardize how your team functions and collaborates on {% data variables.product.prodname_dotcom %}. For more information, see "[GitHub flow](/github/collaborating-with-issues-and-pull-requests/github-flow)" and "[Understanding the GitHub flow](http://guides.github.com/overviews/flow/)" in the {% data variables.product.prodname_dotcom %} Guides.