Code Component have overflow classname for language support

[spencerHT]

• I confirm that this is an issue rather than a question.

Bug report

Steps to reproduce

1. git clone git@github.com:spencerHT/vp-test.git
2. yarn && yarn dev
3. visit http://localhost:8080/guide/using-vue.html
4. find overflowed classname
   

What is expected?

Have no much classname

What is actually happening?

rawCode below with language and other word with "

```ts title="test"
for ts

At packages/@vuepress/markdown/lib/preWrapper.js, token.info.trim() in this case is ts title="test", html resolve finally failed.

<div class="language-ts  title="test" extra-class">

Other relevant information

• Output of npx vuepress info in my VuePress project: