impl a cross platform basic shell for running tasks

like [deno](https://github.com/denoland/deno_task_shell)

also maybe supporting

```js
let xxx = sh`echo "yyy"` 
```
or
```jsx
let xxx = <sh cwd="..." env ={{"PATH": "xxx"}}>echo "yyy"</sh>
```
because we can execute jsx in our repl(