feat: intro and links for simulation-scripts README.txt

[sublimino]

Moved from #332 for commit signing

• Please check if the PR fulfills these requirements

• [*] The commit message follows the conventional commits guidelines
• [-] Tests for the changes have been added (for bug fixes / features)
• [*] Docs have been added / updated (for bug fixes / features)

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

Found empty README.txt in simulation-scripts/scenario/ folder. Added minimal intro text and links for further reading (.md files).

• What is the current behavior? (You can also link to an open issue here)

README.md empty.

• What is the new behavior (if this is a feature change)?

README.md minimal content.

• Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?)

no

• Other information:

alternative solutions:
v1: remove empty README.md
v2: add note why empty README.md needs to be kept