feat: add WindowTitle setting

[nixpig]

Per issue: #436

Set WindowTitle "Live in the Terminal"

[Delta456]

Wow, this looks awesome. Would totally vouch for this to be implemented!

[caarlos0]

this looks great, thank you!

i do think the font of the title could be a bit smaller though... 🤔

[meowgorithm]

Agreed, this one isn’t quite there yet in terms of typography. Can we bump it down a hair and ensure that it only uses exactly the same typeface as the terminal? By default that should be JetBrains Mono (via embedding).

It’s very important for the integrity of the project that we get this one right before merging.

Also, we’ll need to update the README for this as well.

[nixpig]

Cool, thanks for the feedback. I'll get those changes implemented.

[nixpig]

Just wanted to confirm the expected behaviour for a few scenarios:

Scenario	Fonts available on system	Terminal font	Title font
No font specified via Set FontFamily.	JetBrains Mono available on system.	JetBrains Mono from system.	JetBrains Mono from system seems reasonable, but could load from embedding.
No font specified via Set FontFamily.	JetBrains Mono not available on system. Next available on system from defaultFontFamilies is Hack.	Hack from system.	JetBrains Mono from embedding or Hack from system?
No font specified via Set FontFamily.	No fancy fonts from defaultFontFamilies available on system.	Fallback to bare monospace.	JetBrains Mono from embedding or fallback to bare monospace?
Set FontFamily "JetBrains Mono"	JetBrains Mono available on system.	JetBrains Mono from system.	JetBrains mono from system seems reasonable, but could load from embedding.
Set FontFamily "JetBrains Mono".	JetBrains Mono not available on system.	Fallback to bare monospace.	JetBrains mono from embedding or bare monospace?
Set FontFamily "Hack".	Hack available on system.	Hack from system.	Hack from system.
Set FontFamily "Hack".	Hack not available on system.	Fallback to bare monospace.	JetBrains Mono from embedding or fallback to bare monospace?

Any other scenarios not covered above, please add.

Also, should the font file to embed for JetBrains Mono be included in the repo, or add a script/make target to download it from JetBrains at build time, or some other approach?