Merge pull request #27 from threefoldtech/development_v4_kernel

Update v4_3node_guide.md

Author: mik-tf

docs/v4_3node_guide.md

@@ -11,7 +11,9 @@ There are 4 main steps:
 - [Create an account](https://github.com/threefoldtech/tfgrid4-sdk-go/tree/development/node-registrar/tools/account)
 - [Create a farm](https://github.com/threefoldtech/tfgrid4-sdk-go/tree/development/node-registrar/tools/farm)
 - Create a bootstrap image using the [Zero-OS V4 Boot Generator](https://v4.bootstrap.grid.tf/)
-  - Use the Farm ID created in step 2 with the proper network (e.g. main, test, qa or test)
+  - Use the Farm ID created in step 2 with the proper network (e.g. main, test, qa or test)\*
 - [Wipe the disks on your 3Node](https://manual.grid.tf/documentation/farmers/3node_building/4_wipe_all_disks.html)
 - [Set the BIOS/UEFI](https://manual.grid.tf/documentation/farmers/3node_building/5_set_bios_uefi.html)
-- Boot the node with the bootstrap image USB key
+- Boot the node with the bootstrap image USB key
+
+> \*Note: Until the image on the V4 Boot Generator is officially supporting Zero-OS V4 for TFGrid V4, you need to use the expert version of the boot generator and use the following kernel: `zero-os-development-zos-v4-nft-v1.11-debug-6dc6ee97d7efi`. Link: https://v4.bootstrap.grid.tf/expert