Documentation Improvements

[kkarhan]

As the goal of OS/1337 is transparency and reproduceability besides size efficiency and portability to as many platforms as possible, improving the existing build instructions is quite important.

So that ideally one could build it without the existing cofiguration files if needed, which may be necessary in extreme high security, airgapped setups where one could only get the sourcecode in after approval and never get anything out of i.e. critical infrastructure like energy grid operators and even more sensitive systems...

That being said that doesn't change the need to rework the toolchain, but to document better on my part.