Update readme.xrm

Change-Id: Ib4d47071c73fc5f6c48d268a1f00d7f52762dcff
Reviewed-on: https://gerrit.libreoffice.org/8187
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>