Add maze-gen as submodule in showcase

Author: brandonkachen

.gitmodules

@@ -7,3 +7,6 @@
 [submodule "showcase/bayes"]
 	path = showcase/bayes
 	url = https://github.com/narthur/bayes
+[submodule "showcase/maze-gen"]
+	path = showcase/maze-gen
+	url = https://github.com/narthur/maze-gen

showcase/README.md

@@ -6,6 +6,7 @@ Community showcase of projects built by Codebuff
 - [Later](https://github.com/narthur/later) - A task management app inspired by Do It (Tomorrow), built with Svelte
 - [Game of Life](https://github.com/narthur/game-of-life) - Conway's Game of Life implementation with TypeScript
 - [Bayes](https://github.com/narthur/bayes) - A web application for applying Bayesian reasoning to everyday life
+- [Maze Generator](https://github.com/narthur/maze-gen) - A maze generation visualization built with TypeScript
 
 ## Cloning