Docs: Add Parameters API reference

[kylegach]

Contributes to (but does not close): #17243

What I did

• Add a Parameters API reference
• There are very few parameters for Storybook itself, so most of the work is adding API sections to the essential addons docs

See also: storybookjs/addon-kit#61

Checklist for Contributors

Testing

Manual testing

1. Follow the steps in the contributing instructions for this branch, api-ref-parameters

Documentation

• Add or update documentation reflecting your changes
• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

Checklist for Maintainers

• When this PR is ready for testing, make sure to add ci:normal, ci:merged or ci:daily GH label to it to run a specific set of sandboxes. The particular set of sandboxes can be found in code/lib/cli/src/sandbox-templates.ts

• Make sure this PR contains one of the labels below:

  Available labels

  • bug: Internal changes that fixes incorrect behavior.
  • maintenance: User-facing maintenance tasks.
  • dependencies: Upgrading (sometimes downgrading) dependencies.
  • build: Internal-facing build tooling & test updates. Will not show up in release changelog.
  • cleanup: Minor cleanup style change. Will not show up in release changelog.
  • documentation: Documentation only changes. Will not show up in release changelog.
  • feature request: Introducing a new feature.
  • BREAKING CHANGE: Changes that break compatibility in some way with current major version.
  • other: Changes that don't fit in the above categories.

🦋 Canary release

This PR does not have a canary release associated. You can request a canary release of this pull request by mentioning the @storybookjs/core team here.

core team members can create a canary release here or locally with gh workflow run --repo storybookjs/storybook canary-release-pr.yml --field pr=<PR_NUMBER>

[shilman]

Great work @kylegach !! A few minor points

[shilman]

Note: This is only valid in project annotations. It probably should not be a parameter, but we haven't changed it yet

[shilman]

Probably worth clarifying the merge semantics in detail here. Objects are deep-merged, but arrays are replaced.

So merging

{
  a: 'a1',
  nested: { b: 'b1' },
  array: [1, 2]
}

With

{
  a: 'a2',
  nested: { c: 'c2' },
  array: [3, 4]
}

would yield

{
  a: 'a2',
  nested: { b: 'b1', c: 'c2' },
  array: [3, 4]
}