Review request: Islamic Calendar in Plasma

[Fusion Future]

Hello again,

It would be great if someone knows Islamic calendar can give a comment
abouthttps://invent.kde.org/plasma/kdeplasma-addons/-/merge_requests/317

I don't really know how Islamic calendar works so there may be some
mistakes I made unknowingly. Please check the screenshot in the merge
request to see if Islamic calendar shows Islamic date correctly.

Note that the Islamic calendar plugin supports adjusting date offset, which was mentioned earlier when The Islamic Civil Calendar support was introduced.

Thanks in advance!