Bug 543933 - Build javadocs with Java 11

Fix javadoc warnings catched by Java 11 tool with XDoclint:html.

Change-Id: Ief7b6077f08a966426c4312ab1649ac7c84078d2
Signed-off-by: Alexander Kurtakov <akurtako@redhat.com>
diff --git a/org.eclipse.ui.intro.universal/src/org/eclipse/ui/intro/universal/package.html b/org.eclipse.ui.intro.universal/src/org/eclipse/ui/intro/universal/package.html
index dfef24b..dd1ef10 100644
--- a/org.eclipse.ui.intro.universal/src/org/eclipse/ui/intro/universal/package.html
+++ b/org.eclipse.ui.intro.universal/src/org/eclipse/ui/intro/universal/package.html
@@ -13,11 +13,11 @@
 
 Provides a mechanism to add a preference page to customize welcome.
 <h2>Package Specification</h2>
-<p>This package only contains one class, <tt>org.eclipse.ui.intro.universal.ExtensionFactory</tt>.
+<p>This package only contains one class, <code>org.eclipse.ui.intro.universal.ExtensionFactory</code>.
 It provides product developers the ability to add a preference page to customize the welcome
-layout and generate an <tt>introData.xml</tt> file to be included in their final product.
-The class should only be reference from a <tt>plugin.xml</tt> file. For example usage see
-<tt>org.eclipse.platform/plugin.xml</tt>. The preference page is included in the Eclipse SDK
+layout and generate an <code>introData.xml</code> file to be included in their final product.
+The class should only be reference from a <code>plugin.xml</code> file. For example usage see
+<code>org.eclipse.platform/plugin.xml</code>. The preference page is included in the Eclipse SDK
 and can be found under "General -> Welcome".</p>
 
 </body>
diff --git a/org.eclipse.ui.intro/src/org/eclipse/ui/intro/config/package.html b/org.eclipse.ui.intro/src/org/eclipse/ui/intro/config/package.html
index 97a270d..125ced1 100644
--- a/org.eclipse.ui.intro/src/org/eclipse/ui/intro/config/package.html
+++ b/org.eclipse.ui.intro/src/org/eclipse/ui/intro/config/package.html
@@ -14,12 +14,12 @@
 Provides support for customizing welcome content and presentation.
 <h2>Package Specification</h2>
 <p>This package contains the API for customizing the welcome content and presentation. It
-defines two extension points. The <tt>org.eclipse.ui.intro.config</tt> extension
+defines two extension points. The <code>org.eclipse.ui.intro.config</code> extension
 point provides the ability to take full control of welcome and customize all aspects of
-it. The <tt>org.eclipse.ui.intro.configExtension</tt> extension point provides the
+it. The <code>org.eclipse.ui.intro.configExtension</code> extension point provides the
 ability to extend another plug-in's welcome configuration and modify it. For example,
-<tt>org.eclipse.ui.intro.config</tt> could be use to completely redefine the structure
-of the welcome content and <tt>org.eclipse.ui.intro.configExtension</tt> could be used
+<code>org.eclipse.ui.intro.config</code> could be use to completely redefine the structure
+of the welcome content and <code>org.eclipse.ui.intro.configExtension</code> could be used
 to provide a new theme to an existing welcome configuration.</p>
 
 </body>
diff --git a/org.eclipse.ui.intro/src/org/eclipse/ui/intro/contentproviders/package.html b/org.eclipse.ui.intro/src/org/eclipse/ui/intro/contentproviders/package.html
index edf9b22..5eaf5b6 100644
--- a/org.eclipse.ui.intro/src/org/eclipse/ui/intro/contentproviders/package.html
+++ b/org.eclipse.ui.intro/src/org/eclipse/ui/intro/contentproviders/package.html
@@ -11,7 +11,7 @@
 
 Contains classes which can be used to add controls to a welcome page.
 <h2>Package Specification</h2>
-<p>This package contains classes which subclass <tt>IIntroContentProvider</tt> and which can be added
+<p>This package contains classes which subclass <code>IIntroContentProvider</code> and which can be added
 to an intro page either as part of the configuration content or as a configuration extension. These
 allow additional visual content such as a checkbox to be added to an intro page.</p>