Currently, our Playwright Test and Playwright Library pages acknowledges each exist, but don't really spell out the difference between the two.
The goal with this page is:
1. Clarify which package a user should be using
2. If using Playwright Library, show what's required
Depending on the content of this page, it may be possible to make our docs completely `@playwright/test`-first (including the examples), and then just have one doc that answers "if you're using Playwright Library, here's the few unique bits to it that you didn't have to think about in Playwright Test".
The less duplication we have across Library vs. Test docs, the less room there is for confusion and maintenance burden.
@mxschmitt is going to start making the rest of the docs more test-centric once this lands.
