[Mistakes] - Problems in documentation and SmoothGrad batching

[AntoninPoche]

Select the modules to which the bug refers:

• [x] Attributions Methods
• [x] Documentation

Describe the bug There is a problem in the implementation of SmoothGrad :

• [ ] The SmoothGrad method only batch samples on the inputs dimension, not with the nb_samples parameter. Thus is you set a value of 10000 for this parameter, it will make an out of memory error.

There are also several problems in the documentation:

• [ ] There is no documentation on the plots api.
• [x] In the documentation, there should be a link to the source code for each method.
• [ ] The methods are not in alphabetic order, it inders fluidity.
• [ ] The readme methods table should include link to the documentation (maybe the name of the method).
• [x] The documentation for DeconvNet and GuidedBackprop are empty (no description nor link to the paper).
• [ ] The wrong paper is provided for GradientInput, it was actually introduced with DeepLift in https://arxiv.org/abs/1704.02685
• [ ] In xplique.plots.metrics.fidelity_curves the detailed_scores type should be changed from Dict[str, np.ndarray] to Dict[str, Dict[int, float]].

Expected behavior The SmoothGrad method should support high values for nb_samples as inferences do not need to be grouped together.