Convert and move Analytics documentation

Convert the Analytics documentation in cbas-core to AsciiDoc.
Move the converted Analytics documentation to the docs-analytics repo.

We can, of course, leverage the existing pipeline to help with both of these steps.

However simply running the pipeline is not enough. We also have to:

• Edit the AsciiDoc files to remove any information that has been included from the upstream AsterixDB project, and replace each of those chunks with an include using the markdown plugin. Use assembly.yaml to find the chunks that have come from the upstream AsterixDB project.
• We may want to keep the separate Analytics documentation chunks as partials: e.g. REST API documentation.
• Fix any issues that kramdown-asciidoc may not have handled well, e.g. image locations, diagrams, or using a macro for SQL++.
• Handle any replacement edge cases in assembly.yaml, e.g. links or cross-references.