Function change

change<T>(
    doc: Doc<T>,
    options: string | ChangeOptions<T> | ChangeFn<T>,
    callback?: ChangeFn<T>,
): Doc<T>
Update the contents of an automerge document
Type Parameters
- T
  The type of the value contained in the document
Parameters
- doc: Doc<T>
  The document to update
- options: string | ChangeOptions<T> | ChangeFn<T>
  Either a message, an ChangeOptions, or a ChangeFn
- Optionalcallback: ChangeFn<T>
  A ChangeFn to be used if options was a string
  
  Note that if the second argument is a function it will be used as the ChangeFn regardless of what the third argument is.
Returns Doc<T>
Example: A simple change
```
let doc1 = automerge.init()
doc1 = automerge.change(doc1, d => {
    d.key = "value"
})
assert.equal(doc1.key, "value")
```
Example: A change with a message
```
doc1 = automerge.change(doc1, "add another value", d => {
    d.key2 = "value2"
})
```
Example: A change with a message and a timestamp
```
doc1 = automerge.change(doc1, {message: "add another value", time: 1640995200}, d => {
    d.key2 = "value2"
})
```
Example: responding to a patch callback
```
let patchedPath
let patchCallback = patch => {
   patchedPath = patch.path
}
doc1 = automerge.change(doc1, {message: "add another value", time: 1640995200, patchCallback}, d => {
    d.key2 = "value2"
})
assert.equal(patchedPath, ["key2"])
```
- Defined in src/implementation.ts:401