unused file: step-6-clock/startup.c

[seganoff]

First of all huge thanks for this brilliant guide/tutorial !

The issue is, i noticed that in step-6 there is a 'startup.c' file which is not regarded for compilation, its not mentioned in Makefile, but just lays around in folder.
I see its not a big deal. But for an unexperienced reader those little things can be a source of confussion. Especially when already big time confused while dealing with messed up docs from ST.
So just $ rm step-6-clock/startup.c && git commit -am "commit message " && git push

Best wishes

[cpq]

Thank you, done!