feat(mui-theme): add typography field to createTheme function

[henryk1229]

Description

This pr adds a typography field to the createMuiThemeV1 function in mui-theme.ts, which specifies the Karla font family for Spoke components that use the Material-Ui Typography component

Motivation and Context

It closes #1657

This was a request that was part of the feedback for #1641, (see here), but which deserves its own issue + pr

How Has This Been Tested?

Locally.

Screenshots (if appropriate):

https://github.com/politics-rewired/Spoke/assets/47220718/71beeb4f-0e12-40a2-93ff-922ad5fa321f

Documentation Changes

Checklist:

• [ ] My change requires a change to the documentation.
• [ ] I have included updates for the documentation accordingly.

[henryk1229]

I went through each of the options in the admin sidebar just to make sure that the font change didn't throw any existing styling out of alignment, and didn't notice anything. If there's a particular area that anyone wants screenshots or video of, lmk and I can add it above

[ajohn25]

oh should this close #1657 ?