Recommend pipx as default installation method

[micahellison]

Affected Page(s)

https://jrnl.sh/en/stable/installation/

What Could Be Better?

I think it's time to recommend pipx over brew for all OSes.

It's a different world than when the installation docs were written. pipx has become easier to install and hasn't had any packaging issues with jrnl in years, whereas brew takes a long time to install and its lack of isolation has led to frequent issues for jrnl users. Moreover, the maintenance burden of supporting pipx is practically nothing, whereas the added complexities introduced by brew have led to a lot of choring for us rather than working on features.

This isn't to knock brew, which of course has found its place in the big wide world of package managers, but for our purposes, and especially for new users, I think pipx is the answer moving forward.

Other Information

Hat tip to #1886 which also hints at this change.