add short description of program to each file

create_database.rkt

@@ -1,5 +1,8 @@
 #lang racket/base
 
+;; This program creates a sqlite3 database and then creates an empty table
+;; for information on proposals.
+
 (require db)
 
 ; create the database and create the table

update_proposals.rkt

@@ -1,5 +1,7 @@
 #lang racket/base
 
+;; This program updates an entry in a proposals database.
+
 (require racket/cmdline)
 (require racket/date)
 (require db)