fix: add input-overrides examples for evaluations with file attachments

[AAgnihotry]

Summary

Added comprehensive documentation to docs/eval/index.md showing developers how to run evaluations with file attachments using the --input-overrides parameter.

Changes

• Added new subsection "Running Evaluations with File Attachments" to the eval documentation
• Added --input-overrides parameter to the command options table
• Documented input-overrides format and attachment object structure
• Provided three detailed examples:
  1. Single file attachment
  2. Multiple files as an array
  3. Multiple evaluations with different attachments
• Added notes about when the parameter is needed and attachment structure requirements

Documentation Improvements

This documentation helps developers understand:

• How to pass file attachment metadata when running evaluations locally
• The required structure for attachment objects (ID + FullName/MimeType)
• Different use cases for single files, arrays, and multiple evaluations
• Integration with the UiPath eval CLI

🤖 Generated with Claude Code

[smflorentino]

An attachment object must have:

• ID: The file identifier
• FullName OR MimeType: File information

can you clarify this a bit better? is it a file path from where the command is run? why would fullName be optional?

other than that LGTM