Fix repository clone instructions and update directory name in README.md

[gnzng]

While browsing the repo, I noticed a small inconsistency in the repo naming and cloning instructions, which I've addressed in this PR.

I also tried to do a test installation to verify everything works smoothly, and encountered a few challenges that might affect other users as well:

The svmbir package couldn't be built from the conda-forge channel. As a workaround, I commented out that line in environment.yml and was able to proceed with the other dependencies. The environment activated and Jupyter Lab started successfully, though I imagine this might cause issues later in the workflow.

I also ran into some version conflicts when trying to install the latest svmbir via pip. It looks like there are issues with pinned versions.