move customer account ui extension doc to ui extension

[brianshen1990]

Background

move customer account ui extension doc from customer account web repo to ui extension.

• Just copy and adjust build files related to docs => no doc content change
• no ui extension api change

customer account web side PR https://github.com/Shopify/customer-account-web/pull/4676

in customer account web

in ui extension

and the doc and example for each component has been moved to component's folder.

Mainly want to:

1. following admin / checkout / pos's behaviour
2. Try to solve existing type issues ( most of them have been resolved, and a following PR will solve all of them. In this PR I only want to move the files )

🎩

https://shopify-dev.hey.brian-shen.us.spin.dev/docs/api/customer-account-ui-extensions/unstable

• Images works fine
  • static page https://shopify-dev.hey.brian-shen.us.spin.dev/docs/api/customer-account-ui-extensions/unstable
  • reference - component page https://shopify-dev.hey.brian-shen.us.spin.dev/docs/api/customer-account-ui-extensions/unstable/components/card
• example code works file
  • reference - targets https://shopify-dev.hey.brian-shen.us.spin.dev/docs/api/customer-account-ui-extensions/unstable/targets/full-page/customer-account-page-render
  • reference - api https://shopify-dev.hey.brian-shen.us.spin.dev/docs/api/customer-account-ui-extensions/unstable/apis/customer-account-api
  • reference - component https://shopify-dev.hey.brian-shen.us.spin.dev/docs/api/customer-account-ui-extensions/unstable/components/customeraccountaction
• Most of the type references have been resolved automatically ( will resolve the rest of them in a following up PR, this PR is only related to move the files )
  • production type doesn't resolve https://shopify.dev/docs/api/customer-account-ui-extensions/unstable/targets/full-page/customer-account-page-render#standardapi-propertydetail-authenticatedaccount
  • this spin type resolves https://shopify-dev.hey.brian-shen.us.spin.dev/docs/api/customer-account-ui-extensions/unstable/targets/full-page/customer-account-page-render#standardapi-propertydetail-authenticatedaccount

Checklist

• [x] I have :tophat:'d these changes
• [x] I have updated relevant documentation

[github-actions[bot]]

We detected some changes in packages/*/package.json or packages/*/src, and there are no updates in the .changeset directory. If the changes are user-facing and should cause a version bump, run yarn changeset to track your changes and include them in the next release CHANGELOG. If you are making simple updates to repo configuration, examples, or documentation, you do not need to add a changeset.