Better define incubation

[cwilso]

Better define the goals and expectations around incubation. Potential fix for #219.

[tantek]

This better reflects the intent of this principle, and removes the re-use of "incubation" in defining it which is also better form.

[martinthomson]

If your goal is to say something about growing platform capabilities, say that.

Suggested change

	**Incubation**: The Web will continue to expand
	in user base, global reach, and technical breadth.
	We encourage and facilitate incubation in new areas,
	collaborating on innovations across our community.
	We encourage and facilitate careful and responsible exploration of new areas and ideas,
	and intentional collaboration on innovations across our community.
	**New Capabilities**: The Web will continue to expand
	in user base, global reach, and technical capabilities.
	We encourage and facilitate careful and responsible exploration of new areas and ideas,
	and intentional collaboration on innovations across our community.

"incubation" is for eggs.

[cwilso]

I am strongly opposed to removing the word incubation, and disagree that incubation is only for eggs. There is ample evidence of the term in the context of startups and technology.

This point is not about "we should continue to grow the Web platform and add new capabilities". The point is 1) recognize that the web DOES continue to expand, and 2) more importantly, we will be cautious and intentional about how we expand it.