de: review of recent weblate translations by Andrea Bruehlmann

For consistency  within the documentation.de.po I've converted the translated names in angle brackets to upper case.
For consistency with debians git-manpages-de project I've translated "specified multiple times" with "mehrfach
angegeben werden". "Start" as the german translation of "start" isn't wrong, but sounds off, so I replaced it with
"Anfang". Certain words where spelled with "ss" instead of "ß" as Swiss German does not have that letter. I've changed
those to "ß" to keep things standard German. Seeing as Andrea changed other swiss words ("Leerschlag") to standard German
words ("Leerzeichen") in her translations, that seems to be our shared intent.

I've also added Andrea to the contributors list.

Signed-off-by: Matthias Aßhauer <mha1993@live.de>