Many common file systems have a limit of 255 bytes for file and
directory names, and while Git and GitLab both support paths exceeding
those limits, the presence of them makes it impossible for users on
those file systems to checkout a wiki repository locally.

To avoid this situation, we enforce these limits when editing pages
through the GitLab web interface and API:

- 245 bytes for page titles (reserving 10 bytes for the file extension)
- 255 bytes for directory names