Instead of shortening a path segment to just the dot, it is now always
using 2 characters.
E.g.
```
~/.config/nvim/lua/config/lualine.lua
```
is shortened to
```
~/.c/n/l/c/lualine.lua
```
This includes a rewrite of the shortening logic as it cannot be
expressed easily/readable using patterns. The current approach starts at
the beginning and replaces each segment by a shortened version and
keeping track of the overall length (basic book keeping on how many
characters were saved by the replacement).