Migrating over to Mermaid

[jtemporal]

GitFichas is now open source and uses mermaid to create each card. This issue will hold all the improvements that need to happen for the the migration to be considered final in no particular order of priority.

• Fix the renderization of the card in the main page (remove weird top and bottom white space) #62
• Recreate different themes and use them automatically for cards #63
• Automatically link author github on card #64
• Migrate all Portuguese 🇧🇷 cards to mermaid #65
• Create contribution guide #75
• Remove alert from main page #95
• Fix broken renderization on first load #164
• Improve renderization on longer commands #165
• Fix renderization on mobile and smaller viewports #166