Tall Greenhouse

I made the following changes:
* Scaled everything down to 66% so it is slim enough to fit on my flower bench or windowsill
* Elongated the long sides
* Added height to the main body
* Added a baseplate
* Added support structures (inside and outside rims for the baseplate, inside corner pieces for the main body)
* Exchanged the support beams for the top roof (I kept the original angle, but I think it is just a bit too obtuse - see 2nd photo)

Please note that this will only turn out usabl