[Developer Guide Audit] Scheduling

Documentation is the go-to reference for contributors. Parts of the developer guide have been cited as vastly out of date (e.g. referencing VERY outdated versions of docker). We are asking each SIG that owns a portion of the developer guide to audit their [devel guide documentation](https://github.com/kubernetes/community/tree/master/contributors/devel/).

**This does not have to include updating it.**
(although if you want to, please go ahead 😄 )

If you could, update this issue with items that are out of date or you think should be added to the [scheduling](https://github.com/kubernetes/community/tree/master/contributors/devel/sig-scheduling) portion of the devel guide.

Assigning to leads, but please feel free to re-assign and delegate.
/assign @Huang-Wei @ahg-g

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Parent Tracking Issue: #5229
/sig scheduling
/sig contributor-experience
/area developer-guide
/milestone v1.20