[Elecraft] Added LIN OUT measurements

[Jack Smith]

Within the last few minutes, I've added static  harmonic plots at LIN
OUT = 2, 5 and 10 in addition to the GIF animation from 2 to 100 at
http://www.cliftonlaboratories.com/elecraft_k3_receive_audio.htm

The data shows a considerable increase in odd order harmonic distortion
between LIN OUT = 5 and 10.

Looking at the animation, however, should convince the viewer that the
3rd harmonic is consistently down 45 dB over a wide range of LIN OUT
settings (10 to 100.)

Jack