`libsyclinterface` needs description of target audience

[samaid]

For people reading dpctl documentation we need to make a clear distinction of target usages and respective audience. We have two primary audiences:

1. Researchers who want to use dpctl for programming XPUs. For those clear simple install and getting started instructions are required.
2. Python developers who want to create Python libraries and tools that target XPUs. Some are pure Python developers, and they fall in the former category I called "researchers". There is another category of developers that want to use dpctl to write native extensions for XPU. Those may need C API section.

Can you make it clear in the beginning of C API section who is the target audience for this section?

[diptorupd]

As a first step I have renamed what was previously called "C API" to libsyclinterface that is a internal helper library used by dpctl to get a C API for DPC++. I will add a section in the documentation to make the point clear and advise that it is a low-level/internal library that should not be directly used by end-users.