Use relative links for internal content

Relative links should be preferred.

Absolute links are not recommended because
- they're so long which makes them harder to read
- will have to update all the links if
  - the repo is forked
  - the owner of the repo changes
  - the owner's username changes
  - the repo is renamed

For more info, see https://help.github.com/articles/relative-links-in-readmes

P.S. A section on relative links might be useful.

Author: dideler

README.md

@@ -4,34 +4,34 @@ All the hidden and not hidden features of Git and GitHub. This cheat sheet was i
 
 # Contents
 
-- [Ignore Whitespace](https://github.com/tiimgreen/github-cheat-sheet#ignore-whitespace)
-- [Cloning a Repo](https://github.com/tiimgreen/github-cheat-sheet#cloning-a-repo)
-- [Hub - Git Wrapper](https://github.com/tiimgreen/github-cheat-sheet#hub---git-wrapper)
-- [Previous Branch](https://github.com/tiimgreen/github-cheat-sheet#previous-branch)
-- [git.io](https://github.com/tiimgreen/github-cheat-sheet#gitio)
-- [Gists](https://github.com/tiimgreen/github-cheat-sheet#gists)
-- [Keyboard Shortcuts](https://github.com/tiimgreen/github-cheat-sheet#keyboard-shortcuts)
-- [Closing Issues with Commits](https://github.com/tiimgreen/github-cheat-sheet#closing-issues-with-commits)
-- [Checking out Pull Requests](https://github.com/tiimgreen/github-cheat-sheet#checking-out-pull-requests)
-- [Cross-Link Issues](https://github.com/tiimgreen/github-cheat-sheet#cross-link-issues)
-- [Syntax Highlighting in Markdown Files](https://github.com/tiimgreen/github-cheat-sheet#syntax-highlighting-in-markdown-files)
-- [Commit History by Author](https://github.com/tiimgreen/github-cheat-sheet#commit-history-by-author)
-- [Empty Commits](https://github.com/tiimgreen/github-cheat-sheet#empty-commits)
-- [Comparing Branches](https://github.com/tiimgreen/github-cheat-sheet#comparing-branches)
-- [Line Highlighting in Repos](https://github.com/tiimgreen/github-cheat-sheet#line-highlighting-in-repos)
-- [Emojis](https://github.com/tiimgreen/github-cheat-sheet#emojis)
-- [Images/GIFs](https://github.com/tiimgreen/github-cheat-sheet#imagesgifs)
-- [Quick Quoting](https://github.com/tiimgreen/github-cheat-sheet#quick-quoting)
-- [Styled Git Status](https://github.com/tiimgreen/github-cheat-sheet#styled-git-status)
-- [Styled Git Log](https://github.com/tiimgreen/github-cheat-sheet#styled-git-log)
-- [Git Query](https://github.com/tiimgreen/github-cheat-sheet#git-query)
-- [Merged Branches](https://github.com/tiimgreen/github-cheat-sheet#merged-branches)
-- [Quick Licensing](https://github.com/tiimgreen/github-cheat-sheet#quick-licensing)
-- [TODO Lists](https://github.com/tiimgreen/github-cheat-sheet#todo-lists)
-- [.gitconfig Recommendations](https://github.com/tiimgreen/github-cheat-sheet#gitconfig-recommendations)
-    - [Aliases](https://github.com/tiimgreen/github-cheat-sheet#aliases)
-    - [Auto-correct](https://github.com/tiimgreen/github-cheat-sheet#auto-correct)
-    - [Color](https://github.com/tiimgreen/github-cheat-sheet#color)
+- [Ignore Whitespace](#ignore-whitespace)
+- [Cloning a Repo](#cloning-a-repo)
+- [Hub - Git Wrapper](#hub---git-wrapper)
+- [Previous Branch](#previous-branch)
+- [git.io](#gitio)
+- [Gists](#gists)
+- [Keyboard Shortcuts](#keyboard-shortcuts)
+- [Closing Issues with Commits](#closing-issues-with-commits)
+- [Checking out Pull Requests](#checking-out-pull-requests)
+- [Cross-Link Issues](#cross-link-issues)
+- [Syntax Highlighting in Markdown Files](#syntax-highlighting-in-markdown-files)
+- [Commit History by Author](#commit-history-by-author)
+- [Empty Commits](#empty-commits)
+- [Comparing Branches](#comparing-branches)
+- [Line Highlighting in Repos](#line-highlighting-in-repos)
+- [Emojis](#emojis)
+- [Images/GIFs](#imagesgifs)
+- [Quick Quoting](#quick-quoting)
+- [Styled Git Status](#styled-git-status)
+- [Styled Git Log](#styled-git-log)
+- [Git Query](#git-query)
+- [Merged Branches](#merged-branches)
+- [Quick Licensing](#quick-licensing)
+- [TODO Lists](#todo-lists)
+- [.gitconfig Recommendations](#gitconfig-recommendations)
+    - [Aliases](#aliases)
+    - [Auto-correct](#auto-correct)
+    - [Color](#color)
 
 ## Ignore Whitespace