Add misc repo files

[jlillis]

When merged this repo will add some miscellaneous repo files in the .github directory, including:

• CODE_OF_CONDUCT.md (direct copy from mtasa-blue)
• FUNDING.yml (direct copy from mtasa-blue)
• SECURITY.md (direct copy from mtasa-blue

It also updates the security_report template to provide updated guidance on reporting vulnerabilities.

[qaisjp]

CODEOWNERS: I think we can remove lil_Toady and cazomino05 from CODEOWNERS. That would leave me being automatically assigned to admin2 PRs. If you're interested in driving admin2 forward, feel free to add yourself to it.

Coding style

• I think we should leave Coding style for a separate PR just so that the rest of the changes in this PR don't get stuck behind thinking about specific style decisions.
• IMO it's definitely worth at least discussing and documenting the ideal state, even if we can't autoformat or enforce it.
• I think this repository should be a gold standard for what MTA resources look like (and it isn't that right now).
• There's some additional context here about mass code formatting: Add .editorconfig file #247 (review).

[jlillis]

You're right, I think I'll open up a discussion of coding style in a separate issue and leave this as it is for now.

I wasn't aware that CODEOWNERS had that functionality. I'll update it as you described.