[Feature]: Option to set browser font for PTY #81

Problem Statement

Need to set FiraCode Nerd Font ... because of the TUI glyphs.

Currently I need to use dev tools to add a selector

.xterm * {
    font-family: "FiraCode Nerd Font Mono" !important;
}

to make it work. ... And for any created pty.

Proposed Solution

An option to set the font would be nice, so I could set "FiraCode Nerd Font Mono", monospace

Alternatives Considered

... edit the CSS in dev tools on each start ... or add a js bookmarklet in the bookmarks bar to write that css rule to the browser tab.

Use Case

... Pty shows advanced TUI glyphs.

Additional Context

Probably not needed.