Update Downloads links to point at the Releases page, because it seems like the files from @ginatrapani's project (which these linked to) didn't make it to the new org's files, so the links on the redirected page are no good.
* 'Quotes optional.' doesn't make sense for 'addm', because without quotes, 'addm' is 'add'.
* There are no projects that don't start with a +.
* Don't tell people to type uppercase when the software takes care of it.
* Mention actions, mention filtering *out* terms.
* Fix link to wiki in the README
Closes#60