Documentation restructure

[dagardner-nv]

Description

• Restructure documentation per feedback from the documentation team.
• Section headings are no longer their own documents (that is they are not click-able)
  • Most TOCs are now in the root index.md file, section headings are defined with the :caption: directive
  • The exception being situations where a collapsible sub-section is desired.
• Top-level TOCs are marked as :hidden: which prevents the TOC from being displayed in the page body while remaining visible in the side-bar.
• Section headings have been renamed to be more aligned with documentation other Nvidia teams.
• The "why-aiqtoolkit" has been merged into the root index.md document, as much of the information was repeated.
• Consolidate the install and get-started documents into a single quick-start document.
• This PR moves/renames most pieces of documentation, since this will represent the first release under the aiqtoolkit name we are technically not breaking any links.
• Links in the top-level README.md file are no longer https links, and are now relative links into the ./docs/source dir. The reason is that any links to the official released documentation will always refer to the previous release, and the repo needs to be self-referential.
• Links in pypi.md are now versioned links such that the links on https://pypi.org/project/aiqtoolkit/ will always link to the correct version of the documentation. The ci/release/update-version.sh script will update the version in these links.
• In many cases where a document contained both an overview followed by more advanced/detailed information, these have been split into two documents. Ex: docs/source/components/retriever.md has been split into:
  • docs/source/store-and-retrieve/retrievers.md
  • docs/source/extend/adding-a-retriever.md
• advanced has been replaced with extend and reference
• The list of framework integrations has been moved from plugins.md to the installing.md file, as this information is needed by new-users. The rest of the plugins.md document was about authoring a plugin and is more advanced in nature.
• The docs/source/guides/create-customize-workflows.md document is broken out into it's constituent parts and re-organized under docs/source/tutorials
• Add Support and Licensing documents, previously these were sections within the contributing.md file
• Extract the "Launching API Server and User Interface" section from the docs/source/guides/using-aiqtoolkit-ui-and-server.md guide, as this portion was new-user information, while the other portions were more advanced reference documentation.
• The three Observability functions have been grouped together with the following structure:
  • Observe Workflows
    • Observing with Phoenix
    • Observing with W&B Weave

By Submitting this PR I confirm:

• I am familiar with the Contributing Guidelines.
• We require that all contributors "sign-off" on their commits. This certifies that the contribution is your original work, or you have rights to submit it under the same license, or a compatible license.
  • Any contribution which contains commits that are not Signed-Off will not be accepted.
• When the PR is ready for review, new or existing tests cover these changes.
• When the PR is ready for review, the documentation is up to date with these changes.

[mdemoret-nv]

I would like the "What AIQ is Not" section added back into the overview.

[dagardner-nv]

/merge