Consider using shepard (Bikeshed tool) to generate CSS data automatically

[SebastianZ]

This was previously requested in bug 1189440.

The idea is to read the data defined in the CSS specifications to update the JSONs automatically using a tool called shepard:

https://api.csswg.org/shepherd/

Note from @teoli2003:

A priori this is a good idea (it could allow us to have the info before we create a CSS property page and remove the sync need to update CSSData), but we should consider several aspects:

• performance
• can we get all the info needed from it.
• do we need a way to override it (place we diverge from the standard)
• how to deal with pseudo-elements, descriptors, pseudo-classes...

But this is interesting.

Sebastian

[aaronbeall]

Is the data currently maintained by hand?