it seems weird that comments do not get escaped

```go
package main

import (
	"fmt"

	shellquote "github.com/kballard/go-shellquote"
)

func main() {
	dir := "#metoo"
	fmt.Print(shellquote.Join("cd", dir))
}
```

Behavior I get:
```
$ go run . | sh -x
+ cd
$ go run .
cd #metoo
```

Behavior expected:
```
$ go run . | sh -x
+ cd #metoo
$ go run .
cd \#metoo
```

Thank you for creating and maintaining open source software. 🥇 