[Feat] Add images for documentation of raster tools

[wenzeslaus]

Is your feature request related to a problem?

Some tools (modules) have images, some even nice images, in their documentation. It would be great if all raster tools would have images.

See, e.g., here for tools with and without images: https://grass.osgeo.org/grass82/manuals/raster_graphical.html

Adding all images in one PR is not realistic. Instead, this issue will require many PRs by different contributors.

Describe the solution you'd like

Often the documentation contains an example, this can be used to create the image. This is hopefully the most common case.

Some tools may not have examples. Adding an example and an image would be nice.

For some tools, a manually created conceptual image might be a good solution.

For some tools, creating a Jupyter Notebook which creates the image might be a good way of preserving the exact way of creating the image (instead of relying on an example in the documentation).

And for some tools, d.explanation.plot might be quick way to create a conceptual image with real outputs. There is couple of Jupyter Notebooks like that in the repo since d207d49, for example raster/r.series/graphics_for_description.ipynb.

My guess is that the best choice between those might be based on the preference and experience of the contributor, not just based on the tool, i.e., I think that there is usually more than one good solution.

Additional context

Besides the general contributing file, there is a specific guideline for images for documentation at the Trac wiki.

A PR may look like #2577 or #2370. One PR based on this issue can cover one or more tools depending on complexity of the image. One tool can have more than one image, especially if it is more complex or have different kinds on outputs.

Although this issue is created specifically for raster tools (modules), they are not the only ones with missing images in documentation.

[Soumya624]

Hi @wenzeslaus ,

Would love to work on this issue. Kindly assign!

[wenzeslaus]

Sounds great. Assigning the issue is not necessary as the description says:

Adding all images in one PR is not realistic. Instead, this issue will require many PRs by different contributors.

...unless you plan to tackle all of them at once which I don't recommend.

Pick one to start with and create a PR, possibly a draft PR. If you are really concerned about someone else picking the same tool, just write what you are working on here here or open a draft PR soon. I hope this procedure works for you.

[Soumya624]

On it. Thanks :)