Document work around for building documentation on M1 macs where pyenchant doesn't work out of the box

Author: fredvd

docs/contributing/setup-build.md

@@ -40,6 +40,11 @@ cd documentation
 make html
 ```
 
+```{note}
+If you are using an M1 Mac to build the documentation, there is currently an issue with pyenchant that throws an error that the enchant library can't be found. This happens for example if you installed your Python with pyenv. 
+A work around until pyenchant is fixed is to run `export PYENCHANT_LIBRARY_PATH=/opt/homebrew/lib/libenchant-2.dylib`
+in the terminal session before you execute `make html`.
+```
 
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