Add support for YAML anchors and aliases in config files.

[regisphilibert]

Currently this little beauty is only available locally (one file) whereas Huge spreads its configuration into multiple files.

huge/config/Get "scripts" will process the data found in _huge/config/scripts.yaml.
Thus anchors from _huge/config/styles.yaml will not be found.

One big file.

We should look for all the files, concatenate all of their content into one big string (making sure each file's content is stored under a key matching its filename`.

scripts: (scripts.yaml content)
styles: (styles.yaml content)
# ...

This way we'll process every config files as one and users will be able to use anchors across files.