docs: add section titles

Author: kenjis

user_guide_src/source/database/queries.rst

@@ -56,17 +56,26 @@ fetchable results.
 Working with Database Prefixes Manually
 ***************************************
 
+$db->prefixTable()
+==================
+
 If you have configured a database prefix and would like to prepend it to
 a table name for use in a native SQL query for example, then you can use
 the following:
 
 .. literalinclude:: queries/004.php
 
+$db->setPrefix()
+================
+
 If for any reason you would like to change the prefix programmatically
 without needing to create a new connection you can use this method:
 
 .. literalinclude:: queries/005.php
 
+$db->getPrefix()
+================
+
 You can get the current prefix any time with this method:
 
 .. literalinclude:: queries/006.php
@@ -75,6 +84,9 @@ You can get the current prefix any time with this method:
 Protecting Identifiers
 **********************
 
+$db->protectIdentifiers()
+=========================
+
 In many databases, it is advisable to protect table and field names - for
 example with backticks in MySQL. **Query Builder queries are
 automatically protected**, but if you need to manually protect an