Dead tradeoffs link in FAQ (Write tradeoffs.md)

[jeroenhabets]

Expected behavior: Clicking "Check out [tradeoffs|https://github.com/cssinjs/jss/blob/master/docs/tradeoffs.md] for more information." opens filled tradeoffs page.

Describe the bug: Instead I get a 404.

Reproduction: Navigate to: https://cssinjs.org/faq Under item "6. Does JSS has overhead?" Click: "Check out [tradeoffs|https://github.com/cssinjs/jss/blob/master/docs/tradeoffs.md] for more information."

Related to: Issue New docs #932 "Write tradeoffs.md" from 2018.

(This issue will hopefully prevent others from having to search)

[kof]

We used to have this document, not sure what happened.

[jeroenhabets]

For what it's worth: I tried to search the git log but couldn't find a tradeoffs.md (or any file with trade):

git log --name-only|grep trade