We want to enable the community to contribute to the Observatorium project. In order to do so, all active repositories should contain some minimal information.

AC:

• create CONTRIBUTING.md and CODE_OF_CONDUCT.md files in all active repositories in the Observatorium GitHub org: observatorium/thanos-receive-controller, observatorium/observatorium (to be renamed observatorium/api), observatorium/deployments (to be renamed observatorium/observatorium), observatorium/thanos-rule-syncer, observatorium/up, observatorium/operator, observatorium/opa-ams, observatorium/token-refresher