Some relevant documentation issues in Bugzilla for writer and Calc

[ohallot]

For Calc:

POWER(0,0)=1
https://bugs.documentfoundation.org/show_bug.cgi?id=136387

For Writer

Concordance files:
https://bugs.documentfoundation.org/show_bug.cgi?id=136320

Page count
https://bugs.documentfoundation.org/show_bug.cgi?id=135861