Add FP datasheet and trimmer keyword.

Author: nseidle

Footprints/SparkFun-Resistor.pretty/Trimpot_SMD_3.0x3.0mm.kicad_mod

@@ -1,5 +1,7 @@
 (footprint "Trimpot_SMD_3.0x3.0mm" (version 20221018) (generator pcbnew)
   (layer "F.Cu")
+  (descr "https://www.ttelectronics.com/TTElectronics/media/ProductFiles/Datasheet/22.pdf")
+  (tags "Trimmer")
   (attr smd)
   (fp_text reference "Ref**" (at 0 -2.8) (layer "F.Fab")
       (effects (font (size 0.5 0.5) (thickness 0.1) bold))