docs: add reference to the simple docker compose file in the root pro…

[yshyn-iohk]

Description:

In this PR:

• add the reference to the simplest docker-compose file in the root project
• fix the links to the old documentation portal in the OAS

Checklist:

• My PR follows the contribution guidelines of this project
• My PR is free of third-party dependencies that don't comply with the Allowlist
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• I have checked the PR title to follow the conventional commit specification

[github-actions]

Integration Test Results

20 files  ±0  20 suites  ±0   2s ⏱️ ±0s
55 tests ±0  55 ✅ ±0  0 💤 ±0  0 ❌ ±0 
97 runs  ±0  97 ✅ ±0  0 💤 ±0  0 ❌ ±0 

Results for commit f31a303. ± Comparison against base commit 63aca52.

♻️ This comment has been updated with latest results.

[github-actions]

Unit Test Results

104 files  ±0  104 suites  ±0   20m 36s ⏱️ +59s
882 tests ±0  874 ✅ ±0  8 💤 ±0  0 ❌ ±0 
889 runs  ±0  881 ✅ ±0  8 💤 ±0  0 ❌ ±0 

Results for commit f31a303. ± Comparison against base commit 63aca52.

♻️ This comment has been updated with latest results.

[coveralls]

coverage: 48.691%. remained the same
when pulling f31a303 on fix/1484
into 63aca52 on main.