Make sure we specify the tool optimizes single cells in a first step

[FredericHirschmueller]

Bachibouzouk commented on 31 May

When people from oemof dev meeting read our website they had the impression the tool connects and optimizes many cells together

We should add a point under "The tool is under developpment" explaining that we first simulate a single cell

[Bachibouzouk]

@FredericHirschmueller, @c-moeller - I would gladly add whatever content you provide me (now you should provide both EN and DE :))