Feature or optimization description
目前通过引入css的方式设置主题有点繁琐，通过属性设置主题简化，并且每一个terminal实例可以单独控制主题
预期效果:
<template>
<terminal name="my-terminal" theme="dark"><terminal>
</template>
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4
