[Docs] Produce Score Entry Documentation and Alternatives

# Documentation Required

[X] New Document
[ ] Update Document

We need to write some documentation that informs venue minders how to enter scores into the system and some ways of dealing with issues when things are not working correctly. (Contingency if you will) Such as uploading images from file so that we can bypass camera permissions if the end user has said "no" to DERT Info app accessing the camera.

# Audience

This documentation is for End USers and event organisers so that they know how to upload scores and what to do if things aren't playing as expected.

# References

# Additional

Start by reviewing the DERT Info app's current score-entry and image-upload experience, including the camera-permission case. Identify the steps venue minders and event organisers need, then document normal score uploads and file-based alternatives for failures. Done means end users can follow the guide and recover when camera access is unavailable.

Written by the indexing model from the issue text.