Dash docset

[Decipher]

I've put together a Simply.js docset for Dash (http://kapeli.com/dash) which would be useful to anyone wanting to use it.

You can find it at https://github.com/Decipher/simply.js.docset

It should be contributed to Dash, but the checklist for contributing docsets (https://github.com/Kapeli/Dash-User-Contributions/wiki/Docset-Contribution-Checklist) specifies that it should be maintained, and I can't commit to that personally.

[Meiguro]

Wow, thanks for making this! I can definitely maintain it. I'll close this when it's contributed or I provide a suitable alternative.