[Kernel-Kit] I propose adding the possibility of completely offline kernel recompilation

[ChrysoliteAzalea]

Hello everyone! I propose adding the possibility to re-compile the kernel without Internet connection. This can be needed, because Puppy Linux is sometimes used on the old hardware, that may require modified kernel (for example, to add some drivers), but may lack the Internet connection. As far as I understand, the following is required:

• Instead of writing Git repository addresses into the scripts, these repositories should be registered as submodules
• Kernel-Kit should be able to use the local source archive (it already can, but it's not obvious from the documentation)