DOCS: Product Hunt

[huynhicode]

📑 Summary

This PR contains the following updates:

• homepage: add Product Hunt badge
• docs: add promo bar
• docs > Mermaid Chart page: update Product Hunt Badge

Resolves #n/a

📏 Design Decisions

Design decisions made by the Mermaid Chart team.

📋 Tasks

Make sure you

• 📖 have read the contribution guidelines
• 💻 have added necessary unit/e2e tests.
• 📓 have added documentation. Make sure MERMAID_RELEASE_VERSION is used for all new features.
• 🔖 targeted develop branch

###: Screenshots

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 79.05%. Comparing base (20b0318) to head (7391b05).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5602      +/-   ##
==========================================
+ Coverage   77.30%   79.05%   +1.74%     
==========================================
  Files         175      175              
  Lines       14535    14535              
  Branches      869      869              
==========================================
+ Hits        11236    11490     +254     
+ Misses       3091     2837     -254     
  Partials      208      208              

Flag	Coverage Δ
e2e	84.58% <ø> (+2.17%)	⬆️
unit	43.37% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

see 12 files with indirect coverage changes