docs(configuration): add missing config options to documentation

[yogeshwaran-c]

Description

Several configuration options defined in src/core/config/defaults.js were missing from the configuration documentation at docs/usage/configuration.md.

The following options have been added to their appropriate sections:

• components (Plugin system section) - Object for component overrides
• fn (Plugin system section) - Object for function overrides
• initialState (Plugin system section) - Object for initial Redux store state
• configs (Core section) - Object for additional configuration values
• fileUploadMediaTypes (Display section) - Array of media type prefixes that trigger file upload UI
• uncaughtExceptionHandler (Core section) - Function to handle uncaught exceptions

Motivation and Context

Fixes #10745

Users looking at the configuration documentation could not find these options, even though they are available and functional. This made it harder to discover and use them properly.

How Has This Been Tested?

• Cross-referenced each option against src/core/config/defaults.js to verify correct types and default values
• Verified the documentation structure and format matches the existing patterns

Screenshots (if appropriate):

N/A

Checklist

My PR contains...

• No code changes (src/ is unmodified: changes to documentation, CI, metadata, etc.)
• Dependency changes (any modification to dependencies in package.json)
• Bug fixes (non-breaking change which fixes an issue)
• Improvements (misc. changes to existing features)
• Features (non-breaking change which adds functionality)

My changes...

• are breaking changes to a public API (config options, System API, major UI change, etc).
• are breaking changes to a private API (Redux, component props, utility functions, etc.).
• are breaking changes to a developer API (npm script behavior changes, new dev system dependencies, etc).
• are not breaking changes.

Documentation

• My changes do not require a change to the project documentation.
• My changes require a change to the project documentation.
• If yes to above: I have updated the documentation accordingly.

Automated tests

• My changes can not or do not need to be tested.
• My changes can and should be tested by unit and/or integration tests.
• If yes to above: I have added tests to cover my changes.
• If yes to above: I have taken care to cover edge cases in my tests.
• All new and existing tests passed.