x/website: add log/slog handler guide (https://golang.org/s/slog-handler-guide)

[bbkane]

What is the URL of the page with the issue?

https://pkg.go.dev/log/slog#hdr-Writing_a_handler

Linking to https://golang.org/s/slog-handler-guide (broken link)

What is your user agent?

Mozilla/5.0 (Android 13; Mobile; rv:109.0) Gecko/115.0 Firefox/115.0

Screenshot

n/a

What did you do?

Head to https://pkg.go.dev/log/slog#hdr-Writing_a_handler

Click on the https://golang.org/s/slog-handler-guide link

What did you expect to see?

A guide about slog handlers

What did you see instead?

"not found"

[ianlancetaylor]

CC @jba

There is indeed no such short link, and I'm not sure what it should link to.

[jba]

This is https://go.dev/cl/494576, which is in progress.
I would rather roll forward by finishing that doc.
I will aim to do so by early next week.