Fix DTD validation

.gitignore

@@ -14,4 +14,13 @@ user-docs/pt/
 user-docs/pt_BR/
 user-docs/ru/
 user-docs/translate
+contributor-docs/de/
+contributor-docs/en_GB/
+contributor-docs/es/
+contributor-docs/fr/
+contributor-docs/html-style
+contributor-docs/id/
+contributor-docs/mo/
+contributor-docs/pt_BR/
+contributor-docs/translate
 user-docs/update-translations

contributor-docs/po/LINGUAS

@@ -1,2 +1,6 @@
+de
 en_GB
+es
+fr
 id
+pt_BR

user-docs/C/what-is-xubuntu.xml

@@ -14,10 +14,13 @@
 	<title>What is Xubuntu?</title>
 
 	<section id="short-introduction">
+		<title>A short introduction</title>
+
 		<section id="a-free-community-developed-operating-system">
 			<title>A Free Community-Developed Operating System</title>
-			<imagedata fileref="../../libs-common/images/what_is_xubuntu/xubuntu_emblem.png" align="right" />
-			<para>Xubuntu is an elegant and easy-to-use desktop operating system that comes with the Xfce desktop environment,
+			<para><literal><inlinemediaobject><imageobject><imagedata fileref="../../libs-common/images/what_is_xubuntu/xubuntu_emblem.png" /></imageobject></inlinemediaobject></literal></para>
+			<para>
+				Xubuntu is an elegant and easy-to-use desktop operating system that comes with the Xfce desktop environment,
 				making it stable, light on resources and configurable.</para>
 			<para>It is perfect for those who want to make the most of their desktops, laptops and netbooks, featuring a modern
 				look and enough features for efficient daily usage. It also works well on older hardware, single-board computers
@@ -34,15 +37,15 @@
 			<para>The "X" in Xubuntu stands for Xfce, the user interface and bundled core applications that come with Xubuntu.
 				The “ubuntu” in Xubuntu denotes its relationship with the Ubuntu base upon which the operating system is built.
 				Xubuntu is pronounced “zoo-bun-too”.</para>
-			<imagedata fileref="../../libs-common/images/what_is_xubuntu/what_makes_xubuntu.png" width="100%" />
+			<para><literal><inlinemediaobject><imageobject><imagedata fileref="../../libs-common/images/what_is_xubuntu/what_makes_xubuntu.png" width="100%" /></imageobject></inlinemediaobject></literal></para>
 			<para>The word "ubuntu" represents the philosophical core of the operating system. Ubuntu can be roughly translated
 				as "humanity towards others." To read more about the philosophy and ideals behind Ubuntu and Xubuntu, please
 				refer to the <ulink url="&ubuntu-philosophy;">Ubuntu Philosophy</ulink> page.</para>
 		</section>
 
 		<section id="releases-and-version-numbering">
 			<title>Releases and Version Numbers</title>
-			<imagedata fileref="../../libs-common/images/what_is_xubuntu/version_numbers.png" align="right" />
+			<para><literal><inlinemediaobject><imageobject><imagedata fileref="../../libs-common/images/what_is_xubuntu/version_numbers.png" /></imageobject></inlinemediaobject></literal></para>
 			<para>Xubuntu produces a new Long Term Support (LTS) release every 2 years. These releases are supported for 3 years
 				and are a popular choice for users that prefer stability over new features. Every 6 months, a new interim release
 				is made available for users who want to use the latest features at the cost of a shorter, 9-month support cycle.
@@ -69,7 +72,7 @@
 
 		<section id="about-free-software">
 			<title>Free and Open Source Software</title>
-			<imagedata fileref="../../libs-common/images/what_is_xubuntu/gnu.png" align="right" />
+			<para><literal><inlinemediaobject><imageobject><imagedata fileref="../../libs-common/images/what_is_xubuntu/gnu.png" /></imageobject></inlinemediaobject></literal></para>
 			<para>The Xubuntu project is entirely committed to the principles of free software development where people are 
 				encouraged to use software that protects their freedoms, view its source code, improve it, and pass it on. You 
 				can find out more about free software and the ideological and technical philosophy behind it at the 
@@ -78,7 +81,7 @@
 
 		<section id="about-linux">
 			<title>Linux</title>
-			<imagedata fileref="../../libs-common/images/what_is_xubuntu/tux.png" align="right" />
+			<para><literal><inlinemediaobject><imageobject><imagedata fileref="../../libs-common/images/what_is_xubuntu/tux.png" /></imageobject></inlinemediaobject></literal></para>
 			<para>Linux was brought to life in 1991 by a Finnish student named Linus Torvalds. At the heart of the Xubuntu 
 				operating system lies the Linux kernel. The kernel is an important part of any operating system, providing the 
 				communication bridge between hardware and software. Read more about Linux at the
@@ -87,7 +90,7 @@
 
 		<section id="about-xfce">
 			<title>Xfce</title>
-			<imagedata fileref="../../libs-common/images/what_is_xubuntu/xfce.png" align="right" />
+			<para><literal><inlinemediaobject><imageobject><imagedata fileref="../../libs-common/images/what_is_xubuntu/xfce.png" /></imageobject></inlinemediaobject></literal></para>
 			<para>Xfce is the lightweight desktop environment used in Xubuntu. It aims to be fast and low on system resources, 
 				while still being visually appealing and user friendly. Xfce embodies the traditional UNIX philosophy of 
 				modularity and reusability. Read more about Xfce at the <ulink url="&xfce-web;">Xfce website</ulink>.</para>