[Datahub] Change typos to Public Sans semi-bold (title) and Source Sans (text)

[ronitjadhav]

Description

This PR introduces a change of title font to 'Public Sans Semi-Bold' and the main font to 'Source Sans'.

Title font: https://fonts.google.com/specimen/Public+Sans?query=public+sans
Main font: https://fonts.google.com/specimen/Source+Sans+3?query=source+sans

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

---

This work is sponsored by Organization ABC.

[github-actions]

Affected libs: ``,
Affected apps: datahub,

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

[coveralls]

coverage: 86.427% (+4.2%) from 82.262%
when pulling fd0c430 on DH-Update-Font-Style
into 463b60b on main.

[tkohr]

Thanks @ronitjadhav ! I've added a commit to make sure the font-weight 600 from the mockups is applied. Let me know if you agree with this change. From my side feel free to merge.

[ronitjadhav]

@tkohr Thank you for the update. I will proceed with the merge.