[Feature] Fallback to --dot_marker in terminals that don't support braille fonts

[12932]

Checklist

• I've looked through the documentation and existing open issues for this feature/feature request.

Describe the feature request

It would be nice to have btm detect if the terminal/console font is able to render braille, and if not, have it fall back to dot_marker on startup

[ClementTsang]

Not sure if I can detect Braille font support specifically, but I can perhaps detect Unicode support at the very least. If that works out I'll probably also add/change some flags so it's easy to override an automatic detection. That said, no guarantees if this approach will work at all...

Regardless, I'll take a look at some point, though if anyone has any ideas it's much appreciated.

[felix91gr]

What makes a terminal not support unicode/braille fonts? Asking (literally) for a friend who just installed btm and can't see the graphics in their full glory

[ClementTsang]

@felix91gr That's usually caused by the terminal not having a braille font to fall back to. Have they tried looking at https://clementtsang.github.io/bottom/0.8.0/troubleshooting/#the-graph-points-look-brokenstrange? For Linux, cjbassi/gotop#18 might be helpful (it's unfortunately something I have little control over other than adding alternatives).

Feel free to open a separate discussion question if there's still issues.