Fix typo in README.md: corrected "human readable" to "human-readable"

[vipocenka]

This PR corrects a typographical issue in the contracts/script/README.md file. The term "human readable" was adjusted to "human-readable", following standard conventions for hyphenating compound adjectives.

Key Changes

• Corrected "human readable" to "human-readable" in the error message example.

Why this PR is necessary

• Enhances the readability and grammatical correctness of the documentation.
• Aligns the README with common English usage for compound adjectives.

Key places to review

• contracts/script/README.md, line containing the error message example.

Checklist before merging

• Ensure documentation changes are clear and concise.
• Confirm no other typographical issues in related files.