RAML is essentially a YAML with a specific schema. Tell your IDE to treat .raml files as .yaml and all the syntax highlighting, etc will work perfect
It appeared to have weirdness from the homepage:
- secured: !include http://remote-host/secured.ymlWhich is invalid YAML.
It turns out this is probably an unfortunate word-wrap in the page, where a non-wrapping text field would better convey the format.