Add Whitespace Warnings as a git til.

README.md

@@ -47,6 +47,7 @@ smart people at [Hashrocket](http://hashrocket.com/).
 - [Stashing Only Unstaged Changes](git/stashing-only-unstaged-changes.md)
 - [Stashing Untracked Files](git/stashing-untracked-files.md)
 - [Verbose Commit Message](git/verbose-commit-message.md)
+- [Whitespace Warnings](git/whitespace-warnings.md)
 
 ### go
 

git/whitespace-warnings.md

@@ -0,0 +1,13 @@
+# Whitespace Warnings
+
+You can configure git to warn you about whitespace issues in a file when you
+diff it. This is handled by the `core.whitespace` configuration. Add the
+following to your `.gitconfig` file:
+
+```
+[core]
+      whitespace = warn
+```
+
+By default, git will warn you of trailing whitespace at the end of a line as
+well as blank lines at the end of a file.