add Owi

[zapashcanon]

• I have not changed the README.md directly.

I saw this too late after I have already filled everything... I'll update it later but I'm opening the PR as a reminder.

[mre]

Hello @zapashcanon,

thanks for your contribution.

The tool looks great, however the README.md file is auto-generated from the files in data/tools. Can you please go ahead and create a new YAML file in that directory with the information for the tool? You can take a look at the existing files to get an idea of the file format.
The README.md will be rendered automatically then, so the manual changes can be reverted.

For more information, also see the contributing guidelines.