* Clarify documentation of SKIP_VERIFY

The documentation clearly documents the empty value as the default,
however at least one user reported this as being unclear. Mark values
explicitly so it is clear what values it can take. This clarifies that
an empty value in fact leaves certificate verification enabled, whereas
it has to be explicitly set to true to disable certificate verification.

Resolves: #12117

Signed-off-by: Alexander Scheel <alexander.m.scheel@gmail.com>

* Update docs/content/doc/advanced/config-cheat-sheet.en-us.md

Co-authored-by: mrsdizzie <info@mrsdizzie.com>

* Update custom/conf/app.example.ini

Co-authored-by: mrsdizzie <info@mrsdizzie.com>

* Update custom/conf/app.example.ini

Co-authored-by: mrsdizzie <info@mrsdizzie.com>

Co-authored-by: mrsdizzie <info@mrsdizzie.com>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>