add README

flex_sensor_pdf/Makefile

@@ -7,7 +7,7 @@ all: $(IMAGES) flex_sensor.pdf
 	convert $< $@
 
 .ms.ps:
-	GHLENABLECOLOR=0 && soelim -r $< | ghighlight | groff -Geptk -ms -Tps > $@
+	groff -Geptk -ms -Tps $< > $@
 
 .ps.pdf:
 	ps2pdf $< > $@

flex_sensor_pdf/README.md

@@ -0,0 +1,11 @@
+# Flex Sensor PDF example
+
+In this example I am using groff with a custom postscript
+[circuitslib](https://github.com/johnstef99/circuitslib-pic) library I created
+to draw simple circuits with groff. You have to download it separately. I am
+also using grap (the `-G` flag) preprocessor to draw the graphs you see in the
+pdf.
+
+The [Makefile](Makefile) is very simple, it converts all jpgs to eps (filetype
+that groff supports) using imagemagic(`convert`) and then uses `groff` to create a
+postscript file that finally is passed to `ps2pdf` to generate the pdf file.