file split and merge
FrontEnd
```html
Document
```
```js
const fileEle=document.querySelector("#fileInput")
const sliceSize=10*1024*1024 // 10MB
const submit=()=>{
const file= fileEle.files[0]
const fileSize=file.size
let start=0;
let end=sliceSize
const filePieces=[]
while(end<=fileSize)
{
const chunk = file.slice(start,end)
filePieces.push(chunk)
start=end
end+=sliceSize
}
if(start