URL construction for member list access using base URL and org ID

[anagha-cmd]

This PR modifies how member list URLs are constructed by using a configurable base URL from environment variables instead of hardcoded values. This change improves flexibility and allows the bot to work with different membership systems. Closes #455
Changes made:

• Added MEMBERS_LIST_BASE_URL as a required environment variable
• Added validation for the new environment variable in config.py
• Updated URL construction in cogs/make_member.py to use the base URL from settings
• Updated documentation in README.md and .env.example to reflect these changes

Testing:

• Tested URL construction with different base URLs
• Verified error handling for invalid or missing base URLs
• Confirmed backward compatibility with Guild of Students URL structure

[CarrotManMatt]

Using the base URL in this way is a good idea! One issue I could forsee is if an alternative membership system didn't have a concept of organisation IDs.

[MattyTheHacker]

The base url stuff here isn't necessary as it's unlikely that any organisation other than the guild will have the same url format so that can be removed. If we're looking at supporting other SUs I suspect that'll be a larger issue with significant refactoring needed to support the different member list formats

[CarrotManMatt]

supporting other SUs I suspect that'll be a larger issue with significant refactoring needed to support the different member list formats

See #253

[MattyTheHacker]

Yeah I think until we're ready to start actioning the config stuff we assume we're just working with the guild. We can start implementing compatibility with other SUs when that's done

[CarrotManMatt]

other SUs

I'd say we can be even more generic than that and just say "membership system"! /lh