Add community health docs

[chartgerink]

It would be fantastic to add more default information to the meta-repository. These will flow downstream into all repo's in the organization. See also the GitHub documentation.

Here is an overview of the docs we can add:

• CODE_OF_CONDUCT.md
• CONTRIBUTING.md
• Discussion category forms
• FUNDING.yml
• GOVERNANCE.md
• Issue and pull request templates and config.yml
• SECURITY.md
• SUPPORT.md