Improve introduction
Tweak readme further
Re-arrange some sections and add editing section
Improve grammar and add list of plugins
Correct typo and change phrase
Tweak language use
Merge pull request #53 from sihil/sihil-revamp-readme

Revamp readme
Restrict build status logo to master

was showing failed due to another branch
Fix issue #54 and improve recovery from simple errors
Merge pull request #55 from sihil/sihil-edit-errors

Fix issue #54 and improve recovery from simple errors
Bump timeout to 30s (try to make Travis CI more reliable)