* Add GUI help button back by jeylau in https://github.com/DeepLabCut/DeepLabCut/pull/2507
What's Changed
* Pull demo data from Zenodo by jeylau in https://github.com/DeepLabCut/DeepLabCut/pull/2440
* Update maDLC_UserGuide.md by Timokleia in https://github.com/DeepLabCut/DeepLabCut/pull/2446
* Fix bug dataset and metadataset fixes DeepLabCut/DeepLabCut2390 by Tetra-quark in https://github.com/DeepLabCut/DeepLabCut/pull/2405
* Bug fix: `add_new_videos(..., extract_frames=True)` by n-poulsen in https://github.com/DeepLabCut/DeepLabCut/pull/2468
* bug fix: empty predictions during video analysis by n-poulsen in https://github.com/DeepLabCut/DeepLabCut/pull/2467
* Update README.md by MMathisLab in https://github.com/DeepLabCut/DeepLabCut/pull/2464
* Update AUTHORS by MMathisLab in https://github.com/DeepLabCut/DeepLabCut/pull/2475
* updated macOS runner to 13 by n-poulsen in https://github.com/DeepLabCut/DeepLabCut/pull/2484
* Update README.md by Timokleia in https://github.com/DeepLabCut/DeepLabCut/pull/2496
* Bump version of `tables` installed during CI by jeylau in https://github.com/DeepLabCut/DeepLabCut/pull/2500
* updated COLAB notebooks to install a CUDA version compatible with DLC by n-poulsen in https://github.com/DeepLabCut/DeepLabCut/pull/2506
* updated package requirements by n-poulsen in https://github.com/DeepLabCut/DeepLabCut/pull/2513
* Test for the presence of snapshot files when using modelzoo by jeylau in https://github.com/DeepLabCut/DeepLabCut/pull/2485
* Version update by AlexEMG in https://github.com/DeepLabCut/DeepLabCut/pull/2514
**Full Changelog**: https://github.com/DeepLabCut/DeepLabCut/compare/v2.3.8...v2.3.9