Update README

Author: quinnj

README.md

@@ -30,13 +30,15 @@ results = DBInterface.execute!(conn, sql) # convenience method if statement prep
 
 stmt = DBInterface.prepare(conn, "INSERT INTO test_table VALUES(?, ?)") # prepare a statement with positional parameters
 
-DBInterface.execute!(stmt, 1, 3.14) # execute the prepared INSERT statement, passing 1 and 3.14 as positional parameters
+DBInterface.execute!(stmt, [1, 3.14]) # execute the prepared INSERT statement, passing 1 and 3.14 as positional parameters
 
 stmt = DBInterface.prepare(conn, "INSERT INTO test_table VALUES(:col1, :col2)") # prepare a statement with named parameters
 
-DBInterface.execute!(stmt; col1=1, col2=3.14) # execute the prepared INSERT statement, with 1 and 3.14 as named parameters
+DBInterface.execute!(stmt, (col1=1, col2=3.14)) # execute the prepared INSERT statement, with 1 and 3.14 as named parameters
 
-DBInterface.executemany!(stmt; col1=[1,2,3,4,5], col2=[3.14, 1.23, 2.34 3.45, 4.56]) # execute the prepared statement multiple times for each set of named parameters; each named parameter must be an indexable collection
+DBInterface.executemany!(stmt, (col1=[1,2,3,4,5], col2=[3.14, 1.23, 2.34 3.45, 4.56])) # execute the prepared statement multiple times for each set of named parameters; each named parameter must be an indexable collection
+
+DBInterface.close!(stmt) # close the prepared statement
 ```
 
 ### For Database Package Developers