README: update documentation, add info on Vagrant

Signed-off-by: Rohit Yadav <rohit.yadav@wingify.com>
README: fix code indents, add section on common problems

Signed-off-by: Rohit Yadav <bhaisaab@apache.org>
Merge pull request #1 from bhaisaab/master

README: update documentation, add info on Vagrant