Improvements for homepage

Dieses Issue hat noch niemand übernommen.

The following was raised by @comradekingu
That particular passage doesn't intrinsically say anything about why it is possible to help Jamulus.
It would be possible anyway, so the user is left wondering what the link between helping and the unknown concept is.

People don't know what the GPL is, and even if they did, there are three versions of that license.
There is also "Play music online. With friends. For free." which makes a bigger point out of it being gratis, which undersells freedom.
The landing side is not a place where the decisions made command any sort of authority.
Invocation of "us" for no reason.
Mac should be "macOS". (like it is in the side-menu)
Erroneous use of an ampersand (&).
Triple self-referencing (and then som), with redundant info in the ingress, not line-shifted at that.
and brings → bringing
Wall of text inducing stress.
Exclamation points after two consecutive sentences for no good reason.
Duplicated button making the website more likely to scroll vertically.
"ASIO is a trademark and software of Steinberg Media Technologies GmbH " should be in a mouse-over.

How about reducing the workload to just the work being done and then look at it all once done to see if something can be improved upon?

_Originally posted by @comradekingu in https://github.com/jamulussoftware/jamulus/pull/2880#discussion_r990443819_

Beginne damit, den Inhalt der Startseite und die in Pull Request #2880 referenzierte Diskussion zu prüfen. Gruppiere die angeforderten Änderungen an Formulierung, Layout, Terminologie und Darstellung, bevor du Änderungen vornimmst. Als abgeschlossen gilt die Aufgabe, wenn die aufgeführten Anliegen zur Startseite konsistent berücksichtigt wurden und die überarbeitete Landingpage als Ganzes geprüft wurde.

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