Backport #16442
The move to render custom/public as within /assets in #15219 missed updating
several documentation pages.
This PR updates this documentation.
Signed-off-by: Andrew Thornton <art27@cantab.net>
* Rename custom/conf/app.ini.sample to custom/conf/app.sample.ini for better syntax light on editor
* rename to app.example.ini
* per @6543 's comment, update all references on docs
Co-authored-by: techknowlogick <techknowlogick@gitea.io>
