[DOCS] Describing the Medical Imaging Subecosystem

[TheCedarPrince]

@jakubMitura14 @cncastillo and I were chatting about the need to describe the Medical Imaging Subecosystem within JuliaHealth. I think what we need is a new section on the JuliaHealth website that discusses the following about this subecosystem:

• What is medical imaging?
• What part of medical imaging does JuliaHealth focus on?
• What tools does JuliaHealth provide for medical imaging?
• What are goals of the medical imaging subecosystem
• Where can I learn more about doing medical imaging work within JuliaHealth?
• Who should I reach out to about medical imagining within JuliaHealth?

Do you think anything else should be added here folks? Any other ideas at the moment?