Update requirements.txt

Author: Tom-van-Woudenberg

requirements.txt

@@ -3,10 +3,9 @@ teachbooks # depends on jupyter-book
 sphinx-inline-tabs
 jupyterbook-patches
 download_link_replacer
+standard-imghdr
 
 # docutils version for reference page formatting
 docutils==0.17.1
 
-# now list the packages (and the respective url) you wish to download from the GitLab package registry
---extra-index-url https://gitlab.tudelft.nl/api/v4/projects/11239/packages/pypi/simple  #temporarily disable
-sphinx-thebe ~= 0.9.9  #temporarily disable
+git+https://github.com/TeachBooks/Sphinx-Thebe