Added Caleb's modifications

Author: jrod454

handout.md

@@ -18,6 +18,26 @@ Start git at a folder
 git init
 ```
 
+Checkout a branch
+```
+git checkout <branch_name>
+```
+
+Creating a new branch
+```
+git branch -b <new_branch_name>
+```
+
+Show all branches
+```
+git branch -a
+```
+
+Commit changes to local repository
+```
+git commit -m"commit_message"
+```
+
 ### Working with Remote Repos
 First we need to add a remote location.
 
@@ -27,6 +47,20 @@ git remote add <name> <url>
 
 
 ## Advanced topics
+### Ignoring files in your repository
+To ignore specific files, you need to create a .gitignore by running
+```
+touch .gitignore
+```
+
+### Cleaning generated files
+Removing files that were recently created that you do not want to ever commit.
+This is done in two steps:
+```
+git add .
+git reset --hard HEAD
+```
+
 ### Removing unwanted directories permanently
 
 ```