Bugfix release

What's Changed

fix iw.set_data by @kushalkolar in #851
add github button to docs by @kushalkolar in #845
retry sklearn datset downloads if 403 error by @kushalkolar in #844
Update docstrings by @kushalkolar in #841
remove Graphic.share_property() and unshare_property() by @kushalkolar in #842
better docs on use in jupyterlab and ipython by @kushalkolar in #843
fix move to pointer for linear and linear region selector by @kushalkolar in #855
Imgui pin to attempt bugfix release by @kushalkolar in #876

Full Changelog: v0.5.0...v0.5.1