WIP: Update install instructions

[gselzer]

This PR updates our installation instructions to reflect:

1. The switch from openjdk via conda to cjdk
2. The use of uv for developer environment setup.

This PR is currently a WIP because the pip installation instructions do not work on my machine - I get the following error raised in the napari-imagej error dialog box:

  File "C:\Users\gjselzer\micromamba\envs\napari-imagej\Lib\site-packages\jpype\_jvmfinder.py", line 204, in get_jvm_path
    raise JVMNotFoundException("No JVM shared library file ({0}) "
jpype._jvmfinder.JVMNotFoundException: No JVM shared library file (jvm.dll) found. Try setting up the JAVA_HOME environment variable properly.

@hinerm I'd appreciate it if you could try out each of these methods and make sure they work on your machine. In the case of non-editable installs (mamba, napari GUI) I don't know how we can test that installation works. It'd also be great if you could confirm that you also get the JVMNotFoundException from the pip installation instructions.

Closes #330

[gselzer]

Also closes #329