[likelihood_ratio_processes] Break up likelihood ratio processes lecture and add new examples (#547)

* Tom's August 12 edits of thre e lectures

* update wald lecture

* minor edits

* update division

* updates

* update new lectures

* updates

* updates

* Tom's minor tweaks to Humphrey's fine new lecture

* updates

* updates

* updates

* updates

* update tag

* Tom's edits of two lectures, August 16 in United lounge

* Tom's second edits for August 16 Montana time

* minor updates

* Tom's August 17 edits of 3 lectures and the bib file

* updates

* fix minor typos

* polishing lectures

* Update lectures/likelihood_var.md

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: thomassargent30 <ts43@nyu.edu>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: 3 people

lectures/_static/quant-econ.bib

@@ -2,6 +2,36 @@
 QuantEcon Bibliography File used in conjuction with sphinxcontrib-bibtex package
 Note: Extended Information (like abstracts, doi, url's etc.) can be found in quant-econ-extendedinfo.bib file in _static/
 ###
+
+@article{shannon1948mathematical,
+  title={A mathematical theory of communication},
+  author={Shannon, Claude E},
+  journal={The Bell system technical journal},
+  volume={27},
+  number={3},
+  pages={379--423},
+  year={1948},
+  publisher={Nokia Bell Labs}
+}
+
+@article{kullback1951information,
+  title={On Information and Sufficiency},
+  author={Kullback, Solomon and Leibler, Richard A},
+  journal={The Annals of Mathematical Statistics},
+  volume={22},
+  number={1},
+  pages={79--86},
+  year={1951},
+  publisher={JSTOR}
+}
+
+@book{kullback1997information,
+  title={Information theory and statistics},
+  author={Kullback, Solomon},
+  year={1997},
+  publisher={Courier Corporation}
+}
+
 @book{friedman1953essays,
   title={Essays in positive economics},
   author={Friedman, Milton},

lectures/_toc.yml

@@ -33,7 +33,10 @@ parts:
 - caption: Statistics and Information 
   numbered: true
   chapters:
+  - file: divergence_measures
   - file: likelihood_ratio_process
+  - file: likelihood_ratio_process_2
+  - file: likelihood_var
   - file: imp_sample
   - file: wald_friedman
   - file: wald_friedman_2