Merge pull request #165 from patrick-kidger/doc-build-fix

Pinned nbformat and and nbconvert versions

Author: patrick-kidger

docs/requirements.txt

@@ -7,6 +7,8 @@ mknotebooks==0.7.1       # Turn Jupyter Lab notebooks into webpages.
 pytkdocs_tweaks==0.0.6   # Tweaks mkdocstrings to improve various aspects
 mkdocs_include_exclude_files==0.0.1  # Allow for customising which files get included
 jinja2==3.0.3            # Older version. After 3.1.0 seems to be incompatible with current versions of mkdocstrings.
+nbconvert==6.5.0         # | Older verson to avoid error
+nbformat==5.4.0          # |
 
 # Install latest version of our dependencies
 jax[cpu]