[Feature Request] HOW TO: Use renderHeaderCell and keep standard sorting features

### I am opening an issue for
vue-easytable

### Issue Type
Feature

### Issue Title
HOW TO: Use renderHeaderCell and keep standard sorting features

### What problem does this feature solve?
This tip explains how to keep the standard sorting features when using renderHeaderCell

### What does the proposed API look like?
> [!NOTE]
> This is a tip and needs no action.

By default, if you use **renderHeaderCell** on a column, you can no longer click the rendered header to perform a sort, you have to click the up/down indicators which is fiddly.

A simple solution is to add the css style: **pointer-events: none;** to you rendered header element(s).

## Example

```html
renderHeaderCell: ({ column }, h) => {
return (

)
},
```

I hope it helps someone.