Link in the "about" section of the repo is incorrect

[marksweb]

Under the "about" section of the repo is a link that 404s.

Currently set to https://probot.github.io/apps/stale/

[Marcono1234]

Also affects the "Website" link on the right of https://github.com/apps/stale (not sure if that is populated from this repository)

[Marcono1234]

Seems to be related to / a duplicate of #349, see comments there, especially #349 (comment)