Improve style (#14)

* Slightly changed y axis of the flicker noise amplitude plot to make it looker bigger

* Decimate the noise psd plots to remove some of the noise towards higher frequencies.

* Fixed legend background of the LNA background noise plot

* Fixed LNA background noise data. There was an incorrect gain setting applied.

* Fixed dgDrive_output_impedance_comparison, because the sense resistor was not subtracted from the plotted results. This affected all devices but the DgDrive.

* Added LTSpice LNA simulation

Author: PatrickBaus