fix Makefile deps

Makefile

@@ -5,13 +5,13 @@ images:
 images/wide.jpg: images
 	convert -size 100x60 xc:skyblue -fill white -stroke black  -draw "ellipse 50,30 40,20 45,270" images/wide.jpg
 
-docs.pdf: images/wide.jpg
+docs.pdf: images/wide.jpg $(wildcard *.sty)
 	pdflatex -shell-escape docs.tex
-test.pdf:
+test.pdf: test.tex $(wildcard *.sty)
 	pdflatex -shell-escape test.tex
 resources.pdf:
 	pdflatex -shell-escape resources.tex
-rules.pdf:
+rules.pdf: rules.tex $(wildcard *.sty)
 	pdflatex -shell-escape rules.tex
 
 all: docs.pdf test.pdf resources.pdf rules.pdf