Replace API documentation redirect with redirect-from

[1ec5]

#10 didn’t work, because it depends on a publishing tool that isn’t present on GitHub Pages. Instead, this PR uses a whitelisted jekyll plugin to create the redirect. I’ve tested this locally to verify that it works with jekyll.

Each time a new release is published, redirect_from must be removed from the old version and added to the new version. Alternatively, we could have index.html be a simple HTML page with a meta redirect. @danpat @daniel-j-h, which approach would you prefer?

[daniel-j-h]

Alternatively, we could have index.html be a simple HTML page with a meta redirect.

Hm both require a bit of manual twiddling, the best solution would be to have Travis build the api docs from the osrm package and publish them here. I'm fine with both solutions in the meantime - we should document it.

[danpat]

Yeah, we should publish the docs automatically and do some sed magic to update links. Project-OSRM/osrm-backend#4395