site/dev/contrib/revert formatting and details

NOTRY=true

Review URL: https://codereview.chromium.org/873483004

site/dev/contrib/revert.md

@@ -3,16 +3,37 @@ How to revert a CL
 
 Using one-click revert
 ----------------------
-  * Find the codereview issue for the CL you want to revert.
-  * Click the "revert" button.
+*   Find the codereview issue for the CL you want to revert.
+*   Click the "revert" button.
 
 Using Git
 ---------
-    * git checkout master
-    * git pull --rebase && gclient sync
-    * git checkout -b <branch_name> origin/master
-    * git log
-    * <Find the SHA1 of the commit you want to revert>
-    * git revert <SHA1>
-    * git cl upload
-    * git cl land
+
+Update the local repository
+
+    git fetch origin master
+
+Create a local branch with origin/master as its start point.
+
+    git checkout -b revert$RANDOM origin/master
+
+Find the SHA1 of the commit you want to revert
+
+    git log origin/master
+
+Create a revert commit.
+
+    git revert <SHA1>
+
+Upload it to rietveld.
+
+    git cl upload
+
+Land the revert in origin/master.
+
+    git cl land
+
+Delete the local revert branch.
+
+    git checkout --detach && git branch -D @{-1}
+