fixed runtime errors

README.md

@@ -0,0 +1,13 @@
+rust port of python in http://neuralnetworksanddeeplearning.com/chap1.html
+
+main goal: me understanding what's going on
+
+done:
+* implementation that 'works' without runtime errors
+
+to do:
+* verify correctness
+* add unit tests
+* train using actual training data
+* evaluate with test/validation data
+* make more efficient