Update Docker Configuration

[raclim]

Changes:

• Addresses deprecation warnings in Dockerfile
• Updates Installation doc with information regarding the base command transition for Docker Compose between v1 and v2. Docker Compose v1 (docker-compose) -> v2 (docker compose).
• Updates Mongo version from 4.4 -> 5.0 in Docker config files.
• Reverts back how slugs are generated in Project and User models, which were causing a mismatch error.
• Updates URL for retrieving p5 examples to temporarily point to the legacy p5 website. Will update once confirmed that they should point to examples on new website.

I have verified that this pull request:

• has no linting errors (npm run lint)
• has no test errors (npm run test)
• 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

[release-com]

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