fix(vaadin-accordion): export vaadin-accordion-panel

[vursen]

Description

This PR adds missing export for vaadin-accordion-panel so it becomes possible to import it from the outside:

import '@vaadin/vaadin-accordion';
import '@vaadin/vaadin-accordion-panel';

Type of change

• Bugfix
• Feature

Checklist

• I have read the contribution guide: https://vaadin.com/docs-beta/latest/guide/contributing/overview/
• I have added a description following the guideline.
• The issue is created in the corresponding repository and I have referenced it.
• I have added tests to ensure my change is effective and works as intended.
• New and existing tests are passing locally with my change.
• I have performed self-review and corrected misspellings.

Additional for Feature type of change

• Enhancement / new feature was discussed in a corresponding GitHub issue and Acceptance Criteria were created.

[CLAassistant]

All committers have signed the CLA.

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
0.0% Duplication

[web-padawan]

LGTM, thanks 👍 This is now in line with vaadin-tabs and vaadin-tab entrypoints.