Add ssh server functionality

[ivantsepp]

This adds a -server flag which will spin up an ssh server that executes the slides bubbletea application upon each ssh session.

👋 hey apologies for the delay in this PR but here's what I have so far just as a first step in getting ssh functionality! It's very bare bones but intentional because I'm not sure how y'all wanted this functionality to look like.

• I saw this recent wish commit charmbracelet/wish@3a1ac79 and figured we probably want this middleware style so we can eventually send messages to the bubbletea program.
• Uses -server flag since I wasn't sure how you wanted the cli to look like. Should we do something similar to Networked play over ssh gambit#3 where it uses coral to split the cli into subcommands? (ex. slides serve file.md -port 2222 ...)
• I added a server struct similar to the PR for gambit as I imagine we'll extend this later on.
• I didn't attempt to code up how you can have "viewers" - I think there are so many options/ideas and I'm not sure I can handle that part of the coding with my current golang skills 😆

One idea for the ssh functionality is to either require a password (slides serve file.md -password [...] -port 2222 ...) or if it's not given, print out a random password. Then when an ssh session connects with the right password, that session will get presenter rights. Other ssh sessions will automatically be viewers. Thoughts?

[maaslalani]

Hey! This looks super awesome! I'll test it out soon.

Thank you so much for this PR, can't wait to have ssh functionality in slides 🎉

[maaslalani]

Hey, so I think that -server shouldn't be a flag but rather we should have slides serve as the entry point and also be able to pass in the slides through stdin like

# this
slides serve file.md

# or
cat file.md | slides serve

# or 
curl https://raw.githubusercontent.com/maaslalani/slides/main/examples/slides.md | slides serve

so that people don't need to have the slides available on the machine they are hosting the server on.

[ivantsepp]

thanks for taking a look and I totally agree! I followed the gambit PR and added a serve subcommand via the coral/cobra library

[maaslalani]

Absolutely fantastic work! Thanks so much @ivantsepp