Fix main_classes docs index
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_The documentation is not available anymore as the PR was closed or merged._ Hmm it's still not good 
![image](https://user-images.githubusercontent.com/42851186/158429361-e19ce25b-c259-4ded-8473-075deafdbb96.png)

any idea what could cause this ? Ok fixed :)
Currently the `main_classes` documentation has a wrong index. I believe this comes from issues in the examples of the Translation feature types

![image](https://user-images.githubusercontent.com/42851186/158426345-2ee1ceef-ddf3-4a6f-a93e-d1a8f38a44f5.png)

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