Documentation build configuration

In each repository a file called .scotty-docbuilds can be placed. It contains a dictionary of the builds that should be done, when this repository is part of the manifest.

Each key of the dictionary looks like this

"<build name, as shown in the github UI>"": {
    "<key>": "<value>",
    ...
},

Each node is a key-value map just altering the values that are specific to this particular build (the rest will remain on sane default values). Please make sure that only strings are used.