Removing unnecessary lines from the git page

Since the last change, I don't think we need to include git 'command' or
git version

common/git.md

@@ -74,14 +74,6 @@
 
 `git reset --hard HEAD`
 
-- Checking git version
-
-`git --version`
-
 - Calling help
 
-`git --help`
+`git --help`
-
-- Executing git command
-
-`git {{command}}`