docs: new maintainer
docs: new maintainer

Signed-off-by: Krzysztof Nowak <ec2e6b092344a8f9a548dde0d2ede1e06ecfeabd@cern.ch>

inveniosoftware/invenio-communities,inveniosoftware/invenio-communities,inveniosoftware/invenio-communities,inveniosoftware/invenio-communities