Clarify title bar: "About" -> "Docs"

[trentmc]

Background / motivation

In the title bar of predictoor.ai, the title bar item "About" leads to docs.predictoor.ai.

Yet that's a bit weird. We do want to lead to docs, but labeling it "About" is a bit of a misnomer. Docs do include the about, but it's so much more.

Let's call it what it is: "Docs". That's standard practice in most websites.

TODO

Rename "About" to "Docs" in the title bar.

[trentmc]

cc @KatunaNorbert or @kdetry . A quick one for either of you. Thank you.