Add security policy to repo

[CAM-Gerlach]

Adds a security policy to the repo following our modern standards

[ccordoba12]

@CAM-Gerlach, please amend your commit to include a new line with [ci skip] in it. That way, it won't trigger our CIs (That's not necessary given that this doesn't touch our code).

[CAM-Gerlach]

Done. From a brief look at the job output, updating to the latest setup-miniconda action (and checkout action) and modern Python versions for the matrix might just fix this, if there aren't deeper compatibility issues with newer Python versions. I can give it a quick crack if it's worth doing.

I'm curious, what depends on this? It has nearly 50k monthly downloads on PyPI, 1/3 that of Spyder, despite having no updates in 5 years (thus not counting updates and clients where it is already cached).

[ccordoba12]

Thanks @CAM-Gerlach!

[ccordoba12]

I can give it a quick crack if it's worth doing.

Sure, please do if you have some free time.

I'm curious, what depends on this? It has nearly 50k monthly downloads on PyPI

I really don't know.