typo fix Update README.md

[MonkeyKing44]

Title:

Fix typo in README.md

Description:

This pull request corrects a typo in the README.md file of the hardhat-zksync repository. The word "overriden" was changed to "overridden" for accuracy.

Changes Made:

• Corrected the typo from overriden to overridden in the following line:
  From: Here is a list of overriden tasks where this plugin adds new optional parameter \--verify`: To:Here is a list of overridden tasks where this plugin adds new optional parameter `--verify`:`

Testing/Validation:

• No testing required, as this is a documentation fix.

Related Issues:

• No related issues.

Checklist:

• Code follows the project's coding style
• Documentation has been updated
• PR is ready for review