platform_manifest_twrp_omni/omni-aosp.xml

<?xml version="1.0" encoding="UTF-8"?>
<manifest>

  <remote  name="github"
           fetch="https://github.com/" />

  <remote  name="omnirom"
           fetch="https://github.com/omnirom"
           review="gerrit.omnirom.org" />

</manifest>