Add Table-Templates to support Build-Measure-Learn-Documentation

A thing thats missing in Aha! is the support of the Lean Startup Build-Measure-Learn-Feedback-Loop. The most lean way I could think of integrating this is to add a tables as templates, so you can build your own version of this https://digitaleneuordnung.de/blog/lean-startup-methode/

This is to further support the process of validated learning by providing a place to formulate hypotheses, define experiments, and to document the results and the learning from this process