Update on Record3D Dataset (small fixes + documentation) (#286)

* updated dataset to deal with downscale factor and dataset size.

* added docs.

* updated resizing array to always guarantee size of dataset.

docs/tutorials/data/choosing_dataset.md

@@ -65,4 +65,20 @@ Download
 
 ```yaml
 dataset_format: mipnerf_360
-```
+```
+
+###### Record3D
+
+```{button-link} https://record3d.app/
+:color: primary
+:outline:
+Download
+```
+
+```yaml
+dataset_format: record_3d
+```
+
+Directly import dataset recorded from a >= iPhone 12 Pro using the Record3D app.
+
+Record a video and export with the `EXR + JPG sequence` format. Unzip export and `rgb` folder before training.