[Datahub] Update Default Main and Title Fonts to Rubik and Readex Pro

[ronitjadhav]

Description

This PR updates the default main and title fonts used in the Datahub application. The changes are as follows:

• The main font has been changed to 'Rubik'.
• The title font has been changed to 'Readex Pro'.

Quality Assurance Checklist

• Commit history is devoid of any merge commits and readable to facilitate reviews
• If new logic ⚙️ is introduced: unit tests were added
• If new user stories 🤏 are introduced: E2E tests were added
• If new UI components 🕹️ are introduced: corresponding stories in Storybook were created
• If breaking changes 🪚 are introduced: add the breaking change label
• If bugs 🐞 are fixed: add the backport <release branch> label
• The documentation website 📚 has received the love it deserves

[github-actions]

Affected libs: ``,
Affected apps: datahub,

• 🚀 Build and deploy storybook and demo on GitHub Pages
• 📦 Build and push affected docker images

[coveralls]

coverage: 86.337% (+3.0%) from 83.385%
when pulling 05f238b on DH-Default-Font-Update
into c319ec6 on main.

[github-actions]

📷 Screenshots are here!

[jahow]

Thanks!