docs: add a note about Code of Conduct template

[CBID2]

Description

This PR adds a note that mentions GitHub providing a Code of Conduct template to the maintainer intro course. This helps new open source maintainers know that there is another way to create this file when building their project's repository.

Related Tickets & Documents

Closes #195

Mobile & Desktop Screenshots/Recordings

Steps to QA

Tier (staff will fill in)

• [ ] Tier 1
• [ ] Tier 2
• [ ] Tier 3
• [x] Tier 4

[optional] What gif best describes this PR or how it makes you feel?

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[CBID2]

@CBID2 I left some reviews here. 🙂

If you have other ideas, please let me know.

Thanks!

Hey @adiati98. Your ideas were what I thought, so I don't have any new ideas 😊