snapcraft.io/docs: pages starting with docs- redirect outside of snapcraft.io/docs

[degville]

Expected behaviour

Docs pages published with a URL starting with docs- should be published to snapcraft.io/docs/docs-.

Instead, publishing a page from the index (https://forum.snapcraft.io/t/snap-documentation/11127) that has a destination URL that starts with docs- seems to conflict with snapcraft.io/docs.

Steps to reproduce the problem

In the index Discourse page, create a destination URL starting with docs-, such as:

| 1 | docs-roadmap | https://forum.snapcraft.io/t/the-docs-roadmap/8763 |

When linked to from another doc or the navigation, the destination URL for this will be a non-existent page at https://snapcraft.io/<page> instead of https://snapcraft.io/docs/<page>.

eg. https://snapcraft.io/docs-roadmap instead of https://snapcraft.io/docs/docs-roadmap: