Changes from round of JOSS review

[Yurlungur]

PR Summary

This is to address comments in #427 . Thanks @guadabsb15 for the suggestions!

• Add discussion of sanity checks to getting started
• Make build/bin more consistent in documentation
• Add comment about python path
• Make sure figures display in all browsers by making png versions

PR Checklist

• Adds a test for any bugs fixed. Adds tests for new features.
• Format your changes by using the make format command after configuring with cmake.
• Document any new features, update documentation for changes made.
• Make sure the copyright notice on any files you modified is up to date.
• After creating a pull request, note it in the CHANGELOG.md file.
• LANL employees: make sure tests pass both on the github CI and on the Darwin CI

If preparing for a new release, in addition please check the following:

• Update the version in cmake.
• Move the changes in the CHANGELOG.md file under a new header for the new release, and reset the categories.
• Ensure that any when='@main' dependencies are updated to the release version in the package.py

[guadabsb15]

I think that this buildidir should be build? just like the ones on line 13 and 14. I saw there was a change in name and probably that one was forgotten.

[junghans]

Correct, my mistake!

[junghans]

Suggested change

	cmake --build build --parallel
	cmake --install build # optional: install into directory defined via CMAKE_INSTALL_PREFIX
	cmake --build builddir --parallel
	cmake --install builddir # optional: install into directory defined via CMAKE_INSTALL_PREFIX

[Yurlungur]

Changed things back to builddir and did a consistency sweep through the docs. Hopefully I got them all now. I also removed the unit tests from getting started.