Bump @docusaurus/core from 2.0.0-beta.14 to 2.0.0-beta.15

Bumps [@docusaurus/core](https://github.com/facebook/docusaurus/tree/HEAD/packages/docusaurus) from 2.0.0-beta.14 to 2.0.0-beta.15.
- [Release notes](https://github.com/facebook/docusaurus/releases)
- [Changelog](https://github.com/facebook/docusaurus/blob/main/CHANGELOG.md)
- [Commits](https://github.com/facebook/docusaurus/commits/v2.0.0-beta.15/packages/docusaurus)

---
updated-dependencies:
- dependency-name: "@docusaurus/core"
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

packages/artplayer-document/package.json

@@ -15,7 +15,7 @@
         "write-heading-ids": "npx docusaurus write-heading-ids"
     },
     "dependencies": {
-        "@docusaurus/core": "2.0.0-beta.14",
+        "@docusaurus/core": "2.0.0-beta.15",
         "@docusaurus/preset-classic": "2.0.0-beta.14",
         "@mdx-js/react": "^1.6.22",
         "@svgr/webpack": "^6.1.0",