Version control in open source or free hardware projects. Standard methodology?

I have a pallet garden project that has morphed from 1 type of pallet garden into 3 types and with several methods of irrigation and water cycling.  Is there a standard method of versioning it?   I have it on youtube on a playlist.  Someone suggested  using Semantic Versioning  on the videos in my playlist to help me and others keep track.   I do video's a lot because talking to the camera helps define problems for me and sometimes other people do suggest solutions.  The project continues to grow. I expect someone to come up with a Stirling or fluidyne method of using solar heat to compress the air in the next couple of months and if they don't I will do it myself.  (It is only 1 psi and 5 watts).   60 litres per hour works 3 pallet gardens together pretty easily.  I have 6 working at the same time right now.  2 vertical. 1 flat and 3 leaning pallet gardens.  I can double that as soon as I build some more.  Brian