re-org docs/

Makefile

@@ -16,4 +16,8 @@ test:
 clean:
 	rm -f THREAD_TABLE.scad
 	rm -f design/THREAD_TABLE.csv
+	rm -f docs/img_prep/*.png
 
+.PHONY: img_prep
+img_prep:
+	@$(MAKE) -C docs/img_prep

docs/marketing.md

@@ -0,0 +1,22 @@
+# What Others do with threadlib
+
+* [Naminukas](https://naminukas.kikaitachi.com), the indoor robot
+* [Vacuum Pen](https://www.prusaprinters.org/prints/30983-vacuum-pen-for-manual-smd-assembly) for manual SMD assembly
+* [Selector front-plate](https://www.prusaprinters.org/prints/77175-mmu2-selector-front-plate-with-direct-pc4m10) for a 3D-printer add-on
+* [Marking Mandrel](https://www.prusaprinters.org/prints/59885-ktmhqv-450500-marking-mandrel-pt-78129032000): Helpful tool to
+  re-assemble Husqvarna motor
+* [Handle knobs](https://www.thingiverse.com/thing:4582241) for doors
+* [Airbrush adapter](https://www.thingiverse.com/thing:4138696)
+* [Cookie stamps](https://www.thingiverse.com/thing:4752743)
+* [RC boat outboard motor](https://www.thingiverse.com/thing:4961385)
+* [Tool holder for Proxxon / Dremel drill press](https://www.thingiverse.com/thing:4484931)
+* [Mason jar blow-off lid](https://www.thingiverse.com/thing:4831014) for
+  beer fermenting
+* [Declination lock knob](https://www.thingiverse.com/thing:4236155) for
+      Meade telescopes
+
+
+# In the News
+
+* [Hackaday Podcast 076](https://hackaday.com/2020/07/17/hackaday-podcast-076-grinding-compression-screws-scratching-pcbs-and-melting-foam/#comments): They like about threadlib exactly what I made it for -
+  its simplicity.