CodeMirror: Web IDL mode

## Web IDL mode

[NamedConstructor=Image(optional unsigned long width, optional unsigned long height)] interface HTMLImageElement : HTMLElement { attribute DOMString alt; attribute DOMString src; attribute DOMString srcset; attribute DOMString sizes; attribute DOMString? crossOrigin; attribute DOMString useMap; attribute boolean isMap; attribute unsigned long width; attribute unsigned long height; readonly attribute unsigned long naturalWidth; readonly attribute unsigned long naturalHeight; readonly attribute boolean complete; readonly attribute DOMString currentSrc; // also has obsolete members }; partial interface HTMLImageElement { attribute DOMString name; attribute DOMString lowsrc; attribute DOMString align; attribute unsigned long hspace; attribute unsigned long vspace; attribute DOMString longDesc; [TreatNullAs=EmptyString] attribute DOMString border; };

MIME type defined: `text/x-webidl`.