3.4.0

AI generated. Reviewed by Johnny.

This release adds a shell hook for fish. Sean Lunsford contributed it
in #12.

Features

• jd.fish is the shell hook for fish. Source it from config.fish.
  It defines jd, jdex, and one command per system, the same as
  jd.sh does. Each one runs bin/jd and moves your shell to the
  folder the program prints. It also puts bin on $PATH. There is
  no fish port of the zsh prompt.

Changes

• test/cases/fish.sh covers the fish hook. It runs fish as a
  subprocess, and skips with one line when fish is not installed. CI
  installs fish, so the tests run there.
• The README lists fish next to bash and zsh, with its own install
  step.