Update font hierarchy globally

[lynwilhelm]

Use Case

Not all available font weights were available in code but design needed an additional middle range of weight to help with distinct visual hierarchy.

Acceptance Criteria

• Update code to reflect adjustments in size and weight to H3 and H4
• Ensure font-weight:500 which is a medium font weight is in the code and used for H4s

Details

Joe and I have discussed this. We will need to meet and sit side-by-side and check the code to ensure nothing is missed once the changes are made.

See master components file for Simularium for typography guidance

This is related to a ticket that depends on this work: https://github.com/simularium/simularium-planning/issues/146