[Doc]: Explain Fuel Version Management

[seandenigris]

We don't load Fuel or specify a version because it is so integral to Pharo and its ecosystem. For example, even Iceberg uses it to store settings. So we don't want to force users to upgrade and mess up other parts of their system.

That said, some Dynabook features require a certain minimum Fuel version (e.g. auto data migration from an older version).

We should document all this and maybe check for the minimum version on load.