Add setup instructions for minio

[Iron-56]

Issue:

Fixes #3975
Adds documentation for minio setup

Changes:

Adds a doc for minio setup and adds minio folder in gitignore

I have verified that this pull request:

• has no linting errors (npm run lint)
• has no test errors (npm run test)
• has no typecheck errors (npm run typecheck)
• is from a uniquely-named feature branch and is up to date with the develop branch.
• is descriptively named and links to an issue number, i.e. Fixes #123
• meets the standards outlined in the accessibility guidelines