feat(emacs): Add telega.el support

Packages the telega-server binary and adds the required mode into
Emacs.

Unread message count is displayed in the modeline, which is neat.

Probably need to figure out some key bindings for this.

tools/emacs/config/init.el

@@ -171,6 +171,7 @@
 (use-package nix-util)
 (use-package nginx-mode)
 (use-package rust-mode)
+(use-package telega :config (telega-mode-line-mode 1))
 (use-package terraform-mode)
 (use-package toml-mode)
 (use-package web-mode)