[digikam-doc] digikam: add external link

[Gilles Caulier]

Git commit b26673ec893d6a98d640a0d6e352781c28d85f86 by Gilles Caulier.
Committed on 03/09/2016 at 18:31.
Pushed by cgilles into branch 'master'.

add external link

M  +3    -3    digikam/intro-database.docbook

http://commits.kde.org/digikam-doc/b26673ec893d6a98d640a0d6e352781c28d85f86

diff --git a/digikam/intro-database.docbook b/digikam/intro-database.docbook
index 07179ee..890d618 100644
--- a/digikam/intro-database.docbook
+++ b/digikam/intro-database.docbook
@@ -40,7 +40,7 @@
         <title>The Sqlite Database</title>
 
         <para>
-            SQLite is a relational database management system, contained in C programming library. SQLite is not directly comparable to client/server SQL database engines such as MySQL, Oracle or PostgreSQL. Rather, it is an embedded SQL database engine, &ie; it is embedded in an end program. SQLite reads and writes directly to ordinary disk files. For device-local storage with low writer concurrency and less than a terabyte of content, SQLite is almost always a better solution. SQLite is fast and reliable and it requires no configuration or maintenance. It keeps thing simple. SQLite "just works".
+            <ulink url="https://sqlite.org">SQLite</ulink> is a relational database management system, contained in C programming library. SQLite is not directly comparable to client/server SQL database engines such as MySQL, Oracle or PostgreSQL. Rather, it is an embedded SQL database engine, &ie; it is embedded in an end program. SQLite reads and writes directly to ordinary disk files. For device-local storage with low writer concurrency and less than a terabyte of content, SQLite is almost always a better solution. SQLite is fast and reliable and it requires no configuration or maintenance. It keeps thing simple. SQLite "just works".
         </para>
 
         <para>
@@ -91,12 +91,12 @@
             <title>MySQL Versus SQLite</title>
 
             <para>
-                MySQL is an open-source, relational database management system, written in C and C++. 
+                <ulink url="https://www.mysql.com">MySQL</ulink> is an open-source, relational database management system, written in C and C++. 
                 Original development of MySQL by Michael Widenius and David Axmark beginning in 1994. Sun Microsystems acquired MySQL in 2008, which was later acquired by Oracle in 2010. MySQL currently works on almost all system platforms (Linux, Microsoft Windows, OS X, SunOS …).
             </para>
 
             <para>
-                MariaDB server is a community developed fork of MySQL server. Started by core members of the original MySQL team, MariaDB actively works with outside developers to deliver the most featureful, stable, and sanely licensed open SQL server in the industry.
+                <ulink url="https://mariadb.org/">MariaDB</ulink> server is a community developed fork of MySQL server. Started by core members of the original MySQL team, MariaDB actively works with outside developers to deliver the most featureful, stable, and sanely licensed open SQL server in the industry.
             </para>
 
             <para>