Add initial README

README

+### Getting Started with GitLab
+
+1. Generate an SSH keypair for GitLab (optional)
+  `ssh-keygen -t rsa -b 2048 -f ~/.ssh/gitlab.cels.anl.gov`
+
+1. Add your SSH public key to your account on GitLab:
+  1. Browse to: https://gitlab.cels.anl.gov/profile/keys
+  1. Click Add SSH Key (top-right)
+  1. Set the title to something meaningful
+  1. Copy your public key and paste it into the Key field
+  1. Click Add Key
+
+1. Add an entry for GitLab in your ~/.ssh/config file (Optional but very convenient)
+
+This will allow you to type something like `git clone gitlab:namespace/project.git` without needing to pass a username, fqdn, or ssh identity to git
+
+```
+Host  gitlab
+  User              git
+  Hostname          gitlab.cels.anl.gov
+  IdentityFile      ~/.ssh/git.cels.anl.gov
+```