message: add developer name, so on flathub it is not empty
diff: <project_license>MIT</project_license>
  <name>Gittyup</name>
  <summary>Graphical Git client designed to help you understand and manage your source code history</summary>
  + <developer_name>Gittyup Community</developer_name>
  <description>
  <p>Graphical Git client designed to help you understand and manage your source code history</p>
  