Reorganize docs

[gibson042]

README.md should focus first (and most strongly) on using Sizzle, since it gets rendered into https://www.npmjs.com/package/sizzle . This includes API documentation currently in the wiki.

Remaining contents would be better placed in CONTRIBUTING.md and linked to from README.md.

[JuanMaRuiz]

Hi @gibson042 I know this is an old issue but do you still need help fo fix it? How can I help? What is the structure do you think is the correct one?

JuanMa

[gibson042]

Well, taking the content from https://github.com/jquery/sizzle/wiki would be a good start. It's been a while since I've given thought to this issue, and I still expect to replace Sizzle within jQuery this year, but Sizzle itself will always remain valuable as a selector engine implementation.

[JuanMaRuiz]

Many thanks @gibson042 I'll try to do it if you think this change is justified.

Best regards.

[espirit]

I just found Sizzle and looked at te github page. It does not show anything about whát sizzle is or does. No I have no clue whether I should look any further.
It would be good to explain in 3 lines what it does, which problem it solves.

[timmywil]

This issue is just about moving the docs from the wiki, which you can find here.