Improve documentation.

README.md

@@ -6,3 +6,13 @@ Wrapper around pdflatex to use pythontex in lyx.
 ## Usage
 
 Modify an existing format converter in lyx (for example pdflatex) to use pythontex-wrapper.sh instead of pdflatex.
+
+You can edit the *CONVERTERS SECTION* in the lyx configuration file ~/.lyx/preferences:
+
+    #
+    # CONVERTERS SECTION ##########################
+    #
+    
+    \converter "pdflatex" "pdf2" "/home/mike/src/latex-stuff/python/lyx/pythontex-wrapper.sh $$i" "latex=pdflatex,hyperref-driver=pdftex"
+
+This will change the pdflatex generator to use the pythontex-wrapper. If no pythontex-code is contained in your document, pythontex will not be run and you will get normal pdflatex output. I could not find a way to generate a pdflatex+pythontex format that works as expected.