Update 'pipelines' topic in User Guide

[ptitzler]

What changes were proposed in this pull request?

This PR

• Updates the Pipelines topic in the Users Guide
• References content URLs that'll 404 until Add 'Pipeline components' topic to the user guide #1839 is merged
• References content URLs that'll 404 until Document best practices for file-based nodes in user guide #1803 is merged
• Closes Update pipelines topic in user guide #1835

How was this pull request tested?

Reviewed the output of make docs

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[kevin-bates]

These updates look good - thank you.