Add a link to the quick start style guidelines

[dayleparker]

I'd like to propose adding a link to the Best practices for writing quick starts resource to this guide to help those writing that content type.
As there doesn't appear to be sections by content type (although quick starts are mentioned in a few places), I wasn't sure of the best location and would rather trust the SSG maintainers to decide.

The UXD Hub resource was created by Red Hat UXD & docs teams and combines style guidance for writing PatternFly quick start content that we found spread across multiple links and sites:
https://www.uxd-hub.com/entries/resource/best-practices-for-writing-quick-starts

The aim is to help content creators and reviewers create more consistent quick starts following a single source of truth, especially in the Red Hat Hybrid Cloud Console (content was also sourced from the OpenShift docs link). See HCCDOC-2517 for more info on this initiative.

I've been adding the link to various sites, so feel free to reuse the language from PRs such as
https://github.com/patternfly/patternfly-quickstarts/pull/322/files or RedHatInsights/quickstarts#245, or the Content Types Source page. Let me know if I can help with this - thanks!