Document hashtext() and Friends?

Hackers,

Is there a reason that hashtext() and friends are not documented? Given that they’re likely to be used more and more
forpartitioning and sharding, I think it would be useful to do so, starting with something like this. Comments? 

*** a/doc/src/sgml/func.sgml
--- b/doc/src/sgml/func.sgml
***************
*** 1557,1562 ****
--- 1557,1577 ----       <row>        <entry>         <indexterm>
+          <primary>hashtext</primary>
+         </indexterm>
+         <literal><function>hashtext(<parameter>string</parameter>)</function></literal>
+        </entry>
+        <entry><type>int</type></entry>
+        <entry>
+         Generate a hash value for string.
+        </entry>
+        <entry><literal>hashtext('greetings, human')</literal></entry>
+        <entry><literal>-1132466231</literal></entry>
+       </row>
+
+       <row>
+        <entry>
+         <indexterm>          <primary>left</primary>         </indexterm>
<literal><function>left(<parameter>str</parameter><type>text</type>, 

Best

David