feat: add behind indicator

[5c077yP]

related to #67, this adds another git behind indicator. unfortunately i didn't really work with svg before so i just added a pure utf "↓". to keep consistency i removed the ahead svg and also replaced it with a pure utf "↑" . If this goes against your design a will revert and try to add an svg instead.

this is how it looks for me:

also because there's no svg, there was no special need for custom colors, which is why i also removed them.

[j-f1]

This included in #78, which I’ve published to @j-f/hyper-statusline. You can swap hyper-statusline with @j-f/hyper-statusline in your config to switch.