changes to training-contribution-process.rst

removed extra spaces
changed mail to e-mail
added a , after know
changed sentences for playing with your network
fixed the spelling for splitting
changed play to be engaged
changed wording under choosing a question

Change-Id: I0798dedf64e0a01af3f5fdfc0c82b9a04c8a45a4
Merge "changes to training-contribution-process.rst"