Add project: markdown-svgbob

[nschlemm]

What kind of change does this PR introduce?

• [x] Add a project
• [ ] Update a project
• [ ] Remove a project
• [ ] Add or update a category
• [ ] Change configuration
• [ ] Documentation
• [ ] Other, please describe:

Description:

Add the great svgbob extension for Python Markdown which renders diagrams using svgbob.

You can try it out using the Svgbob Editor or the AsciiGrid Editor.

Checklist:

• [x] I have read the CONTRIBUTING guidelines.
• [x] I have not modified the README.md file. Projects are only supposed to be added or updated within the projects.yaml file since the README.md file is automatically generated.

[pawamoy]

svgbob is impressive. Thanks for sharing!

[nschlemm]

de rien!