Figure out how to include multiple markdown files in the generated docs

[brimoor]

I would like to have the README.md and APPLICATIONS.md files be top-level files in the sidebar of the generated docs, but I cannot figure out how to do this.

The current build process just puts README.md in the generated index.html, and ignores (I think?) the APPLICATIONS.md.

The workaround is to link to https://github.com/voxel51/api-js/blob/develop/APPLICATIONS.md on github.com from the README, but it would be preferable to be able to link to an HTML version on our website...