Add dbt-deltastream documentation

[Kayrnt]

What are you changing in this pull request and why?

This PR adds comprehensive documentation for DeltaStream adapter configurations in dbt.
The PR covers:

• Add documentation pages for the dbt deltastream adapter (setup & resource config)
• Add pages in the sidebar
• Update community adapter page

Related Links:

• DeltaStream dbt adapter: https://github.com/deltastreaminc/dbt-deltastream

To learn more about the writing conventions used in the dbt Labs docs, see the Content style guide.

Checklist

• The changes in this PR meet the docs style guide/fundamentals required for all content.
• Applied the proper versioning rules if the content is for specific dbt version(s): (version a whole page or version a block of content)
• The content in this PR requires a dbt release note, so I added one to the release notes page.

ADDING OR REMOVING PAGES (if so, uncomment):

• Add/remove page in website/sidebars.js
• Provide a unique filename for new pages

[welcome]

Hello!👋 Thanks for contributing to the dbt product documentation and opening this pull request! ✨
We use Markdown and some HTML to write the dbt product documentation. When writing content, you can use our style guide and content types to understand our writing standards and how we organize information in the dbt product docs.
We'll review your contribution and respond as soon as we can. 😄

[vercel]

@Kayrnt is attempting to deploy a commit to the dbt-labs Team on Vercel.

A member of the Team first needs to authorize it.

[mirnawong1]

hey @Kayrnt , thanks for creating this pr! some of the team is at our coalesce analytics engineering event this week and we're review this as soon as we can! cc @amychen1776