Make demo template

[krestenlaust]

• [x] Reference to figure in text
• [x] Math
• [x] Bulleted lists and other types of common formatting.
• [x] Use of footnote
• [x] Use of sources
• [x] Code view (possibly with line numbers)
• [ ] Various graphs
• [ ] Picture with caption
• [ ] Tables
• [ ] Appendix

Resolves #10

[krestenlaust]

I've postponed fixing CI/CD to a later release, as I'm sure how to fix it with the knowledge I have now

[krestenlaust]

The following features can be added later: Various graphs Picture with caption Tables Appendix