Replace CADET-Python in the documentation with CADET-Process

[ronald-jaepel]

This PR replaces CADET-Python in the documentation with CADET-Process. The installation section is update to install CADET-Process and the example is adapted to a simple Langmuir BT CADET-Process example. Beyond that it just links to the CADET-Process documentation.

fixes #194

[jbreue16]

Do we really want to get rid of any documentation and even mention of cadet-python?

[schmoelder]

Hey @ronald-jaepel thanks for updating this!

Do we really want to get rid of any documentation and even mention of cadet-python?

I agree with @jbreue16 here. I think we should ask ourselves, what is the purpose of this introduction?

Do we want to give a practical example using CADET-Python? Then I would refer people to the old Tutorials.

Do we want to give a practical example using CADET-Process? Then I would refer people to the CADET-Process documentation or the Workshop material.

Do we want to introduce the interface? Then maybe we should not be so "hands-on" and rather explain the different sections of the interface. But this could also done in the "Interface" section of the documentation.

Do we want to give an overview of the overall architecture of CADET (Core, Python, Process)? Then, we could instead use something like the following figure:

[ronald-jaepel]

AFAIK (as the previous structure of the website was) the purpose of this introduction is a "Hello World" example in the "Getting Started" section. So users come to the website, install CADET, try a simple example, and then can move on to more detailed documentations from there. If we want to re-structure the website later, we can still do that later but for now I do not want any more people coming to the forum with CADET Python code and "I learned this on the website". So I either want to throw the CADET Introduction out completely or replace what it did with CADET-Process.

Do we want to give a practical example using CADET-Python? Then I would refer people to the old Tutorials.

If we want to do that I can add a link to the old tutorials. With the warning, that CADET-Python is outdated.

Do we want to give a practical example using CADET-Process? Then I would refer people to the CADET-Process documentation or the Workshop material.

I already link to the CADET-Process documentation. However, the CADET-Process documentation is large and can be overwhelming to new users (it was for me). The Workshop material, as you've said before, isn't meant to be worked through alone. So having a super simple example on the main CADET website still serves a purpose imo.

Do we want to introduce the interface? Then maybe we should not be so "hands-on" and rather explain the different sections of the interface. But this could also done in the "Interface" section of the documentation.

We don't here, because, as you said, it's in the interface section of the documentation.

Do we want to give an overview of the overall architecture of CADET (Core, Python, Process)? Then, we could instead use something like the following figure:

That figure is also getting outdated quickly. It doesn't contain any representation of the interchangeability of CADET backends (Core vs Julia vs Python). I wouldn't put it on the website as it is right now.

[jbreue16]

Ive added some changes to minimalistically include cadet-python. I think cadet-python has to be documented somewhere and ive tried to introduce it with only the necessary information while pointing out that we recommend cadet-process. As part of that Ive decided to call cadet-python "API" and only refer to cadet-process as a "frontend".

The changes are just a suggestion, please feel free to change anything you like!

[jbreue16]

Another alternative that came to my mind is to move the cadet-python documentation to the developer guide. This way, its still documented but hidden from the average user who will default to cadet-process.