Add in user documentation for configs

[NathanKelly-ONS]

User documentation for configs

Summary

Created a readme file for the new configs. PR to merge into the 733 branch as the 733 branch is the branch that actually implements the new config, so will need to familiarise yourself with the new config as part of the review. It's a fairly simple change from a user-facing perspective, just splitting the config into a user config and a dev config. The user config has the bucket name, filepaths and period information, and the dev config has everything else.

Type of Change

• Bug fix
• New feature
• Breaking change
• Documentation update
• Other (please describe):

Checklists

This pull request meets the following requirements:

Creator Checklist

• Installable with all dependencies recorded
• Runs without error
• Follows PEP8 and project-specific conventions
• [N/A] Appropriate use of comments, for example, no descriptive comments
• [N/A] Functions documented using Numpy style docstrings
• [N/A] Assumptions and decisions log considered and updated if appropriate
• [N/A] Unit tests have been updated to cover essential functionality for a reasonable range of inputs and conditions
• [N/A] Other forms of testing such as end-to-end and user-interface testing have been considered and updated as required

If you feel some of these conditions do not apply for this pull request, please
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Reviewer Checklist

• Test suite passes (locally as a minimum)
• Peer reviewed with review recorded

Additional Information

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