support kitty terminal graphic protocol

[mgcsysinfcat]

the protocol that allows the program running in the terminal to render arbitrary pixel (raster) graphics to the screen of the terminal emulator

A program similar to browsh has implemented this protocol, enabling it to offer a browsing experience in the terminal that's nearly identical to that of a regular GUI browser.

[mikeslattery]

FYI, this is no longer a niche protocol. The Kitty graphics protocol is supported by Kitty, Konsole, Warp, Wezterm, Ghostty, iTerm2, and st w/patches. I'd guess most people that want browsh would likely switch terminals if they thought they could get higher fidelity images.

As @mgcsysinfcat mentioned, awrit is a competing Chrome-based in-terminal browser, but it's 100% graphical. I'd prefer to use browsh as it's mostly text based and only uses graphics in places where it must. But until sixel is replaced with kitty graphics, I'll be using awrit.