added README file to explain the structure in rmd/

Author: Thomas Manke

rmd/P04_Colours.Rmd

@@ -0,0 +1,9 @@
+Lecture material (0*, 1*)
+  The main training material: typically takes 4-5 half-day sessions
+
+Projects (P*)
+  these are larger and concrete projects that relied on material covered
+
+Small Extras (S*): 
+  these Rmd provide short summaries that where done for specific courses
+  may substiute the longer lecture material if time is short