reorganize all the parts into subdirectories

src/ was getting pretty unreadable and I finally had time to do
something about it

Signed-off-by: Brian S. Stephan <bss@incorporeal.org>

src/misc/rocker-20mm-plate.scad

@@ -0,0 +1,17 @@
+/*
+ * SPDX-FileCopyrightText: © 2023 Brian S. Stephan <bss@incorporeal.org>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+include <parameters.scad>
+include <components.scad>
+use <neutrik-d-plate.scad>
+
+module rocker_plate_20mm() {
+	difference() {
+		neutrik_d_plate();
+		rocker_20mm_mount();
+	}
+}
+
+rocker_plate_20mm();