Patternfly React Astro update

[dlabaj]

Update this repo to use the new Astro based documentation framework found in patternfly-doc-core repo. This includes completing the following:

• Use the Astro based doc-core to build the documentation in this repo.
• Update patternfly-org to pull in this repos newly built astro based documentation.
• Update the staging site and verify it's showing the new astro content.

[kmcfaul]

Update org to pull in react repo