FEAT: Add an example for helix

[godalming123]

Hi, I think that helix would be a good showcase for this. Helix is a full-featured text editor written in rust, it uses the linux terminal, but would be very hard to port, as the following needs to be implemented first:

• A compiler for rust to create WASM, that can be ran in browsix
• A terminal that supports ANSI character sequences (implemented in [Semi-WIP] Rewrite terminal based on xterm.js; redirecting stdin, using dash #65)