Adding Git cartoons by Allison Horst. (#360)

Adding https://allisonhorst.com/git-github. 

Also, alphabetized section.

README.md

@@ -2073,13 +2073,14 @@ function Squash-Commits {
 
 * [19 Git Tips For Everyday Use](https://www.alexkras.com/19-git-tips-for-everyday-use) - A list of useful Git one liners
 * [Atlassian's Git tutorial](https://www.atlassian.com/git/tutorials) Get Git right with tutorials from beginner to advanced.
-* [Learn Git branching](https://learngitbranching.js.org/) An interactive web based branching/merging/rebasing tutorial
 * [Getting solid at Git rebase vs. merge](https://medium.com/@porteneuve/getting-solid-at-git-rebase-vs-merge-4fa1a48c53aa)
+* [Git and GitHub Cartoons](https://allisonhorst.com/git-github) – Cartoons by Allison Horst that showcase how to use Git.
 * [Git Commands and Best Practices Cheat Sheet](https://zeroturnaround.com/rebellabs/git-commands-and-best-practices-cheat-sheet) - A Git cheat sheet in a blog post with more explanations
 * [Git from the inside out](https://codewords.recurse.com/issues/two/git-from-the-inside-out) - A tutorial that dives into Git's internals
 * [git-workflow](https://github.com/asmeurer/git-workflow) - [Aaron Meurer](https://github.com/asmeurer)'s howto on using Git to contribute to open source repositories
 * [GitHub as a workflow](https://hugogiraudel.com/2015/08/13/github-as-a-workflow/) - An interesting take on using GitHub as a workflow, particularly with empty PRs
 * [Githug](https://github.com/Gazler/githug) - A game to learn more common Git workflows
+* [Learn Git branching](https://learngitbranching.js.org/) An interactive web based branching/merging/rebasing tutorial
 * [learnGitBranching](https://github.com/pcottle/learnGitBranching) - An interactive git visualization to challenge and educate!
 
 ## Scripts and Tools