Formatted all pages according to guidelines.

pages/common/git-add.md

@@ -1,19 +1,19 @@
 # git add
 
-> Adds changed files to the index
+> Adds changed files to the index.
 
-- Add a file to the index
+- Add a file to the index:
 
 `git add {{PATHSPEC}}`
 
-- Add all files (tracked and untracked)
+- Add all files (tracked and untracked):
 
 `git add .`
 
-- Only add already tracked files
+- Only add already tracked files:
 
 `git add -u`
 
-- Also add ignored files
+- Also add ignored files:
 
 `git add -f`