[Feature] Could you add a feature to adjust heatmap cell size?

### What problem does this feature solve?

Hello, I’m using Heatmap with Echarts.
I set the x,y coordinates to `type:value` and use a heatmap, but the cell size is fixed to 1 both horizontally and vertically.
Is there a function to adjust width and height? If not, can you please apply it?
I desperately need it.. 😂😂

### What does the proposed API look like?

option = {
grid: {
height: ‘50%’,
width: ‘40%’,
top: ‘10%’,
left: ‘30%’,
},
xAxis: {
type:’value’,
splitArea:{
show:true
},
splitNumber: 1
},
yAxis: {
type:’value’,
splitArea:{
show:true
},
splitNumber: 1
},
series: [
{
name: ‘Field’,
type: ’heatmap’,
coordinateSystem:’cartesian2d’,
itemStyle: {
color:’#ffdddd’,
borderWidth:1,
borderColor:’#000’
},
data: [[0.5,0.5,0.5],[-0.5,-0.5,-0.5]]
}
]
};