README: Added info about setting branch --tracking

To setup remote tracking of the branch stable/v1.0
git checkout with --track option can be used:
	git checkout -b stable/v1.0 --track origin/stable/v1.0
Otherwise when git checkout -b stable/v1.0 is used
branch may not be properly set up to track it's remote counterpart
(given git option) and users may be confused due to no files present
in the folder, but README.

Signed-off-by: Piotr Gregor <[email protected]>
Acked-by: Sebastian Andrzej Siewior <[email protected]>
Signed-off-by: John Kacur <[email protected]>

Author: Piotr Gregor

README

@@ -4,3 +4,19 @@ The master branch is unused. You should use an existing branch instead.
 
 The stable/v1.0 branch contains the old stable version.
 The unstable/devel branches contain the development versions.
+
+
+BRANCH CHECKOUT
+
+To list available branches for tracking please do:
+	git branch -r
+
+To checkout stable/v1.0 and setup remote tracking to /origin/stable/v1.0 please do:
+	git checkout -b stable/v1.0 origin/stable/v1.0
+or
+	git checkout -b stable/v1.0 --track origin/stable/v1.0
+
+Older versions of git will not work with git checkout stable/v1.0.
+
+Similarly for the unstable/devel/v1.1.1 branch please do:
+	git checkout -b unstable/devel/v1.1.1 --track origin/unstable/devel/v1.1.1