[docs] Some activation functions are missing images #65368
Description
📚 Documentation
In #5457, images were introduced in the pages of each activation functions. Now, there are a few of them that are missing their images:
Three of them are already in the build_activation_images.py. So, the fix is really simple: add the other two to the script and fix the docstrings of all these 5 functions.
If this is of interest, I could send this PR: rodrigoberriel@aee963c
Lastly, I didn't change it, but I guess we could remove the line below, because of this discussion in #5457. If so, I can update when sending the PR.
I didn't open the PR directly because I guess this is the correct workflow. Please, let me know if I need to open an issue for this kind of straightforward doc change.