Update _index.de.md

[VVzy196]

Added Link for 3,3 V Buck Boost Module

[gluap]

Hi @VVzy196, that one is indeed our weak point and a new working link is much appreciated - However we had a few "this one should work cases" in the past, so to make sure that this one is indeed the working one, could you describe what tests you did to ensure this?

Example: In the past we had one where we thought it was working and later it turned out to be limited to the 3.8-4.2V range and below that it failed. We had another one where approximately 2 out of three were working but every third was broken... Did you do extensive measurements or just had a good experience with the link? How many of these did you use in OpenBikeSensors.

Again: We really appreciate the link, but we had multiple instances of supposedly-good links that were in the end not so good, so I'm asking for some more detail.