Add GitHub source links to directory paths in architecture overview

[Aniketsy]

References and relevant issues

Description

while going through docs, i thought its good to add link, so that anyone can direcly jump there.

[brisvag]

Isn't there a "smart" sphinx way of pointing to the generated API docs instead? Though that isn't pointing to the files anymore in that case... not sure :P

[Aniketsy]

Isn't there a "smart" sphinx way of pointing to the generated API docs instead?

Sorry not familiar, i needs to look into this.

[psobolewskiPhD]

I don't know of a way to link to the codebase directly, but you can link to the API docs using, e.g.:

{meth}`~napari.Viewer.add_labels`