A cross between a spreadsheet and a database

Planned features
- Real time collaboration
- Native performance
- Database-backed data storage (supports joins, schema based instead of cell based, etc.)

TODO:
[] Improve font rendering with msdfgen
[] Add caret (and the capability to edit text anywhere)
[] Formula bar
[] Add cell labels along the top and left (A, B, C, ...; 1, 2, 3 ...)
[] Remove lib/imgui/examples? (need to check if this is possible)