[DRAFT/PROPOSAL] change naming/documentation approach from 'Airgapped Docs' to offline documentation

[CamrynCarter]

The Airgapped Docs section is somewhat misleading, because it looks like a section of the documentation on how to set up an airgapped environment. The documentation also treats "Airgapped Docs" as an additional product, instead of a feature addition to Carbide that can be installed/enabled.

The goal of this PR is to lessen that confusion by changing the reference to "offline documentation". This is self-explanatory but moves away from the "airgapped" language used throughout the rest Carbide documentation to describe setting up the product in an airgapped environment. Offline is also less prescriptive and could appeal to customers in low/off-and-on connectivity but not full airgap.

Question... I take it the carbide chart is named 'airgapped-docs'? Could we change this to 'offline-docs' for consistency if we want to proceed with this change?