Fix typo.

doc/src/sgml/external-projects.sgml

 <!--
-$PostgreSQL: pgsql/doc/src/sgml/external-projects.sgml,v 1.2 2004/12/03 06:04:38 momjian Exp $
+$PostgreSQL: pgsql/doc/src/sgml/external-projects.sgml,v 1.3 2004/12/03 06:18:12 momjian Exp $
 -->
 
  <chapter id="external-projects">
@@ -176,7 +176,7 @@ $PostgreSQL: pgsql/doc/src/sgml/external-projects.sgml,v 1.2 2004/12/03 06:04:38
    extensible. For this reason, extensions loaded into the database can
    function just like features that are packaged with the database. The
    <filename>/contrib</> directory shipped with the source code
-   contains a large number of extensions. The <filename>READMD</> file
+   contains a large number of extensions. The <filename>README</> file
    in that directory contains a summary. They include conversion tools,
    full-text indexing, <acronym>XML</> tools, and additional data types
    and indexing methods. Other extensions are developed independently,