Add Verbose Commit Message to til.

git/verbose-commit-message.md

@@ -0,0 +1,10 @@
+# Verbose Commit Message
+
+Git allows you to display a *diff* of the staged changes in the commit
+message buffer. This gives you the opportunity to carefully craft your
+commit message in a way that accurately describes the changes being
+committed. To display the diff when committing:
+
+```bash
+$ git commit -v
+```