Expand developer contribution docs with conda-native workflow

[jezdez]

What is the idea?

To lower the barrier of entry for contributors that don't have pixi installed on their machine, let's expand the contributing docs in the Developer Guide to list a conda-only way as well (favoribly as the first item in the list of options).

Why is this needed?

Lower barrier for contribution for conda users.

What should happen?

I would suggest to use conda-project (if we want to retain a project management focus), conda-lock (for reproducible environemts) or simply a plain conda environment.yml. Maybe we can also look at other conda incubated projects to follow precedence.

Additional Context

No response

[travishathaway]

Let's add an environment.yml to the repository and add documentation for how to create a development environment using it.

[travishathaway]

@jezdez,

Please see the following pull request:

• Add conda native development environment setup #36