feat: adding readme block with instructions to main page

[amelnytskyi]

What ❔

Added readme instructions to "Intro.md" page

Why ❔

Checklist

• PR title corresponds to the body of PR (we generate changelog entries from PRs).
• Tests for the changes have been added / updated.
• Documentation comments have been added / updated.

[github-actions]

API E2E Test Results

207 tests  ±0   207 ✅ ±0   18s ⏱️ -1s
 14 suites ±0     0 💤 ±0 
  1 files   ±0     0 ❌ ±0 

Results for commit d0d3187. ± Comparison against base commit 25d20d7.

♻️ This comment has been updated with latest results.

[github-actions]

Visit the preview URL for this PR (updated for commit d0d3187):

• https://staging-scan-v2--pr246-qa-806-add-readme-to-3eknngch.web.app
• https://staging-storybook-scan-v2--pr246-qa-806-add-readme-to-kon3ws6z.web.app

_{(expires Wed, 24 Apr 2024 13:49:21 GMT)}

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_{Sign: e508f9012944951194447cb8885950b451a24403}

[github-actions]

Unit Test Results

    4 files  ±0    263 suites  ±0   11m 4s ⏱️ +2s
2 081 tests ±0  2 080 ✅ ±0  1 💤 ±0  0 ❌ ±0 
2 289 runs  ±0  2 288 ✅ ±0  1 💤 ±0  0 ❌ ±0 

Results for commit d0d3187. ± Comparison against base commit 25d20d7.

♻️ This comment has been updated with latest results.