doc(faq): explicit the positioning of cloud scanner compared to API and datavizta

[demeringo]

Problem

Potential users ask about differences between datavizta and BoaviztAPI

Solution

Add a section to the FAQ to explain that both tools use the same dataset (i.e. the Boavizta API).

Add also a section about the roadmap (mention future support of Azure instances)

Alternatives

Additional context or elements

[demeringo]

[!NOTE] below paragraph should go to cloud scanner documentation. We should also separate the FAQ section from the common issues sections.

What are differences between Datavizta and Cloud scanner

Both tools rely on the same source of impact data (i.e. the BoaviztAPI. The API is used to estimation the impacts of aws instances.

• Datavizta is positionned as a pedagogical front end to the API. It helps users understand which kind of data the API, quickly test hypothesis. It offers visualizations of impacts of multiple indicators for differents lifecylce steps (use vs manaufacture).

• Cloud scanner is more production oriented. It returns same data as Datavizta but in different form and with different inputs.
  The main objective of cloud scanner is to help quickly retrieve the impacts of an entire AWS account by automating the inventory of resource used and the retrieval of associated impacts.
  In addition cloud scanner can be used as a monitoring system that runs regularly. In this later case, it generates results as metrics (in standard Prometheus / Open metrics format). Theses metrics can be consumed by external systems, to ease further analysis (e.g. breakdown by service / tags or courntries) or use custom visualizations (like an external dashboard).

Which cloud provider or service is supported by cloud scanner

• Only AWS is supported for the time being. The reason is that historically BoaviztAPI could only provide reference data for AWS instances.
• Azure instances are on the roadmap. After data becomes available in Boavizta API, cloud scanner will be adapted to support Azure Support Azure instances #15.
• In addition BoaviztAPI is working on providing impacts of Storage as a service. It will be integrated to cloud scanner once available. Adding storage as a service  boaviztapi#143