Tom's edits of two lectures and toc, Sept 30

Author: thomassargent30

lectures/_toc.yml

@@ -53,6 +53,7 @@ parts:
   chapters:
   - file: odu
   - file: likelihood_ratio_process
+  - file: imp_sample
   - file: wald_friedman
   - file: exchangeable
   - file: likelihood_bayes