add more parts to pcb2

README.md

 
 The PCB designs use a [KiCad-RP-Pico based](https://github.com/ncarandini/KiCad-RP-Pico) symbol and footprint library, licensed as `CC-BY-SA 4.0`.
 
+The `pcb2/extern/EC12E-200.STEP` 3D model for the rotary encoder comes directly from the manufacturer, [ALPS](https://tech.alpsalpine.com/e/products/detail/EC12E24204A8/).
+
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     | This source describes Open Hardware and is licensed under the CERN-OHL-S v2  |
     | or any later version.                                                        |

pcb2/fp-info-cache

-23172866859269130
+23172866879369002
 Audio_Module
 Reverb_BTDR-1H
 Digital Reverberation Unit, http://www.belton.co.kr/inc/downfile.php?seq=17&file=pdf (footprint from http://www.uk-electronic.de/PDF/BTDR-1.pdf)