Bump @vuepress/theme-default from 2.0.0-rc.17 to 2.0.0-rc.18

Bumps [@vuepress/theme-default](https://github.com/vuejs/vuepress/tree/HEAD/packages/@vuepress/theme-default) from 2.0.0-rc.17 to 2.0.0-rc.18.
- [Release notes](https://github.com/vuejs/vuepress/releases)
- [Changelog](https://github.com/vuejs/vuepress/blob/master/CHANGELOG.md)
- [Commits](https://github.com/vuejs/vuepress/commits/HEAD/packages/@vuepress/theme-default)

---
updated-dependencies:
- dependency-name: "@vuepress/theme-default"
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

package.json

@@ -69,7 +69,7 @@
     "@vitejs/plugin-vue": "^5.0.4",
     "@vue/compiler-sfc": "^3.4.21",
     "@vue/server-renderer": "3.4.21",
-    "@vuepress/theme-default": "^2.0.0-rc.17",
+    "@vuepress/theme-default": "^2.0.0-rc.18",
     "compression": "^1.7.4",
     "cross-env": "^7.0.3",
     "express": "^4.18.3",