Update Open edX brand typography via design tokens

[arbrandes]

Description

The Open edX default brand theme needs updated typography to match the elm-theme. This includes switching the font family to Inter, adjusting heading sizes across all levels, and updating display heading weights and mobile breakpoints.

Paragon v23+ resolves styles through CSS custom properties generated fromdesign tokens at build time, so the typography overrides should be provided as a typography.json token file rather than SCSS variables.

PRs

• feat!: correcting the typography of this brand theme. #40
• fix: convert typography overrides to design tokens #41

MFE version bumps

Once the new brand-openedx version is published, each MFE will need its @edx/brand dependency bumped to @openedx/brand-openedx@^2. This must be done individually per repository:

• paragon
• MFE bumps

[arbrandes]

With v2.0.1 of the @openedx/brand package being release, we're unblocked to bump the MFEs.