rename folder to prompt_evaluations and update README

prompt_evaluations/09_custom_model_graded_prompt_foo/prompts.py

@@ -0,0 +1,14 @@
+def basic_summarize(article):
+  return f"Summarize this article {article}"
+
+def better_summarize(article):
+  return f"""
+  Summarize this article for a grade-school audience: {article}"""
+
+def best_summarize(article):
+  return f"""
+  You are tasked with summarizing long wikipedia articles for a grade-school audience.
+  Write a short summary, keeping it as concise as possible. 
+  The summary is intended for a non-technical, grade-school audience. 
+  This is the article: {article}"""
+