Fix naming inconsistencies and glitches in blink demos

[sebromero]

No description provided.

[sebromero]

@Lenardgeorge I removed the storage folder as it doesn't make sense to me to have it. The tutorials should imho be easy to find by their name. Once we have proper and visible categorisation of tutorials also on the documentation page we can reconsider. But for now just having one sketch in a sub-sub folder makes it harder to find if you ask me.

[Lenardgeorge]

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