Fix: update mining documentation (#39)
Cleanup and update the mining documentation.
Also takes some suggestions from iamwacko's EOTK pull request at https://github.com/alecmuffett/eotk/pull/108
Also fixes typos found by jschauma's EOTK pull request at https://github.com/alecmuffett/eotk/pull/106
Closes #39 (closed).