[DOCS] Various small documentation fixes

This pull request is both a code change and a call for help. :) 

I have been stuck in Perforce hell for a few years now and my git skills have been suffering (my private repos are in BitBucket and I only contribute to them, no forks). I rebased my local master branch to avoid having a merge commit, but I might have made things worse. My intent was to merge my small commits into one and send a pull request on that one commit: Can someone provide any pointers to send a better pull request for my last commits? https://github.com/brusic/elasticsearch/commits/docs Contact me privately.