Update google_compute_instance docs - labels field in initialize_params block (#6326) (#4531)

Signed-off-by: Modular Magician <[email protected]>

Author: modular-magician

.changelog/6326.txt

@@ -0,0 +1,3 @@
+```release-note:none
+
+```

website/docs/d/compute_instance.html.markdown

@@ -128,6 +128,8 @@ The following arguments are supported:
 
 * `image` - The image from which this disk was initialised.
 
+* `labels` - A set of key/value label pairs assigned to the disk.
+
 <a name="nested_scratch_disk"></a>The `scratch_disk` block supports:
 
 * `interface` - The disk interface used for attaching this disk. One of `SCSI` or `NVME`.