fix: typos in documentation files

[evg1nn-eth]

Description

This pull request addresses several spelling and grammatical issues across the codebase. These changes help improve code clarity and reduce the likelihood of confusion for contributors and users. Specifically, the following corrections were made:

"PlonK" → "PLONK" (standard notation for the proof scheme, this is an abbreviation that is usually written in uppercase).
"verifer" → "verifier" (a spelling mistake in the word "verifier", which means "the one who verifies").

These fixes were primarily applied in variable names, comments, and documentation.
No new dependencies were introduced as part of these changes.

How Has This Been Tested?

The changes do not affect functionality but improve code readability. As a result, no new tests were needed.
All existing unit and integration tests were run to ensure the correctness of the system.

Key Areas to Review

• New feature
• Bug fix
• Breaking change
• Performance improvement
• Refactoring
• Dependency update
• Documentation update
• Tests

Which Components or Systems Does This Change Impact?

• Validator Node
• Documentation
• Codebase (comments, variable names)
• Full Node (API, Indexer, etc.)
• Move/Aptos Virtual Machine
• Aptos Framework
• Aptos CLI/SDK
• Developer Infrastructure
• Move Compiler
• Other (specify)
• I have made corresponding changes to the documentation

Checklist

• I have read and followed the CONTRIBUTING doc
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I identified and added all stakeholders and component owners affected by this change as reviewers
• I tested both happy and unhappy path of the functionality