BUG: Fix episode links in README content table

Fix episode links in `README` file content table: links have changed
after the transition to the Carpentries Workbench infrastructure.

README.md

@@ -94,15 +94,15 @@ To cite this lesson, please consult with [CITATION](CITATION)
 [slack_channel_status]: https://img.shields.io/badge/Slack_Channel-neuroimaging-E01563.svg
 [binder_url]: https://mybinder.org/v2/gh/carpentries-incubator/SDC-BIDS-dMRI/main?urlpath=lab/tree/code
 [binder_svg]: https://mybinder.org/badge_logo.svg
-[episode01]: https://carpentries-incubator.github.io/SDC-BIDS-dMRI/introduction/index.html
-[episode02]: https://carpentries-incubator.github.io/SDC-BIDS-dMRI/preprocessing/index.html
-[episode03]: https://carpentries-incubator.github.io/SDC-BIDS-dMRI/local_orientation_reconstruction/index.html
-[episode04]: https://carpentries-incubator.github.io/SDC-BIDS-dMRI/diffusion_tensor_imaging/index.html
-[episode05]: https://carpentries-incubator.github.io/SDC-BIDS-dMRI/constrained_spherical_deconvolution/index.html
-[episode06]: https://carpentries-incubator.github.io/SDC-BIDS-dMRI/tractography/index.html
-[episode07]: https://carpentries-incubator.github.io/SDC-BIDS-dMRI/local_tractography/index.html
-[episode08]: https://carpentries-incubator.github.io/SDC-BIDS-dMRI/deterministic_tractography/index.html
-[episode09]: https://carpentries-incubator.github.io/SDC-BIDS-dMRI/probabilistic_tractography/index.html
+[episode01]: https://carpentries-incubator.github.io/SDC-BIDS-dMRI/introduction.html
+[episode02]: https://carpentries-incubator.github.io/SDC-BIDS-dMRI/preprocessing.html
+[episode03]: https://carpentries-incubator.github.io/SDC-BIDS-dMRI/local_orientation_reconstruction.html
+[episode04]: https://carpentries-incubator.github.io/SDC-BIDS-dMRI/diffusion_tensor_imaging.html
+[episode05]: https://carpentries-incubator.github.io/SDC-BIDS-dMRI/constrained_spherical_deconvolution.html
+[episode06]: https://carpentries-incubator.github.io/SDC-BIDS-dMRI/tractography.html
+[episode07]: https://carpentries-incubator.github.io/SDC-BIDS-dMRI/local_tractography.html
+[episode08]: https://carpentries-incubator.github.io/SDC-BIDS-dMRI/deterministic_tractography.html
+[episode09]: https://carpentries-incubator.github.io/SDC-BIDS-dMRI/probabilistic_tractography.html
 [lesson-example]: https://carpentries.github.io/lesson-example
 [link_issues]: https://github.com/conp-pcno-training/SDC-BIDS-dMRI/issues
 [jason_kai]: https://github.com/kaitj