docs: expand VMTYPE description

Note that it's used to gate VM-specific behavior, like virtiofs
mounts on vz.

Signed-off-by: Bitalizer <23104115+bitalizer@users.noreply.github.com>

Author: bitalizer

website/content/en/docs/dev/internals.md

@@ -211,7 +211,7 @@ The volume label is "cidata", as defined by [cloud-init NoCloud](https://docs.cl
 - `LIMA_CIDATA_ROSETTA_ENABLED`: set to "true" if Rosetta x86_64 emulation is enabled in the guest (Apple Silicon, `vz` driver).
 - `LIMA_CIDATA_ROSETTA_BINFMT`: set to "true" if the guest should register the Rosetta binfmt_misc handler at boot.
 - `LIMA_CIDATA_SKIP_DEFAULT_DEPENDENCY_RESOLUTION`: set to "1" to skip Lima's built-in package dependency resolution during provisioning, empty otherwise.
-- `LIMA_CIDATA_VMTYPE`: the VM driver type ("qemu", "vz", "wsl2", ...).
+- `LIMA_CIDATA_VMTYPE`: the VM driver type ("qemu", "vz", "wsl2", ...), used to conditionally enable VM-specific behavior (e.g. virtiofs mounts on `vz`).
 - `LIMA_CIDATA_VSOCK_PORT`: the vsock port used by the guest agent (0 when vsock is not used).
 - `LIMA_CIDATA_VIRTIO_PORT`: the virtio-serial port name used by the guest agent (empty when virtio-serial is not used).
 - `LIMA_CIDATA_PLAIN`: set to "1" when the instance is in plain mode (no mounts, port forwarding, or containerd), empty otherwise.