message: Updated linux appdata xml to add description and keywords,
diff: <project_license>BSD-3-Clause</project_license>
  <metadata_license>BSD-3_Clause</metadata_license>
  <name>Toggl Desktop</name>
  - <summary>Free Time Tracking Software</summary>
  + <summary>Simple and Intuitive Time Tracking Software</summary>
  <description>
  <p>Toggl Desktop is a desktop app for leading time tracking tool Toggl. The Desktop app is a great companion for time tracking and productivity as it has advanced features like:</p>
  <ul>
  <li>Tracking reminder</li>
  <li>Pomodoro timer</li>
  <li>Timeline</li>
  - <li>Autotracker</li>
  </ul>
  </description>
  <keywords>
  - <keyword>toggl</keyword>
  - <keyword>time</keyword>
  - <keyword>tracking</keyword>
  <keyword>productivity</keyword>
  - <keyword>some</keyword>
  - <keyword>other</keyword>
  - <keyword>tags</keyword>
  + <keyword>employee time tracking</keyword>
  + <keyword>work hours</keyword>
  + <keyword>time tracking</keyword>
  + <keyword>timer</keyword>
  + <keyword>work log</keyword>
  + <keyword>timesheet</keyword>
  + <keyword>hours tracker</keyword>
  </keywords>
  <url type="homepage">https://toggl.com</url>
  <!-- <screenshots> -->
  