Enhance the overview of supported nodes

[benkroehs]

In #159 an overview of the supported nodes was initially introduced. This overview is generated by grepping the different NIRNodes in each framework's from_nir or to_nir file. If a NIRNode was found, it is assumed that the framework supports the conversion of this node. The list of supported nodes is updated every Monday.

Improvements

• include primitives that are automatically inherited from nirtorch, such as Linear, Conv2d, ...
• handle Spyx (NIRNodes are just mentioned but conversion is not supported) --> maybe find a more elegant way than grepping
• add NIRData support to overview