Invalid IDL for ShadowAnimation interface

Hello,

I’ve noticed that current IDL for ShadowAnimation interface [1] is not
valid:

[*Constructor* (Animation
<https://www.w3.org/TR/web-animations-1/#the-animation-interface>
source, Animatable <https://svgwg.org/specs/animations/#Animatable>
newTarget) ]
interface *ShadowAnimation* : Animation
<https://www.w3.org/TR/web-animations-1/#the-animation-interface> {
  [SameObject] readonly attribute Animation
<https://www.w3.org/TR/web-animations-1/#the-animation-interface>
sourceAnimation
<https://www.w3.org/TR/SVG2/struct.html#__svg__ShadowAnimation__sourceAnimation>;
};

Per IDL grammar, Constructor cannot be defined with a space before brackets
[2]. The proper IDL would look like this:

[*Constructor*(Animation
<https://www.w3.org/TR/web-animations-1/#the-animation-interface>
source, Animatable <https://svgwg.org/specs/animations/#Animatable>
newTarget) ]
interface *ShadowAnimation* : Animation
<https://www.w3.org/TR/web-animations-1/#the-animation-interface> {
  [SameObject] readonly attribute Animation
<https://www.w3.org/TR/web-animations-1/#the-animation-interface>
sourceAnimation
<https://www.w3.org/TR/SVG2/struct.html#__svg__ShadowAnimation__sourceAnimation>;
};

This is not a big deal, but it breaks parsers like Ruby IDL parser [3].

P.S. I’m not sure if that’s the correct way to report issues like. Sorry if
it’s not.

[1]: https://www.w3.org/TR/SVG2/struct.html#InterfaceShadowAnimation
[2]: https://heycam.github.io/webidl/#Constructor
[3]: https://github.com/jarib/webidl