Update .env.docker to add PHP upload size modifications

[BeatSpark]

Found out you can alter these PHP variables via the .env. I'm not sure if these could be added to other non-docker implementations but I've tested it with our Docker deployment and it works.

[welcome]

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[what-the-diff]

PR Summary

• Improved Documentation for Backup Settings
  More information has been added to the project settings, making it easier for users to understand and adjust the size of their backups if they need to. This information is contained within the .env.docker file.

[snipe]

Hi there - thanks for this! Can you please re-target this PR to point to the develop branch, per our Contributing documentation?

You don't need to close and re-open. After you create a pull request, you can modify the base branch so that the changes in the pull request are compared against a different branch. By changing the base branch of your original pull request rather than opening a new one with the correct base branch, you’ll be able to keep valuable work and discussion.

Thanks!

[CloCkWeRX]

Conflicts

[snipe]

I handled this in a commit elsewhere - thanks!