Add missing section ids in reference documentation

Add missing id attributes to <section> elements in the reference
documentation to ensure stable anchor links in HTML output.

Issue: SPR-9346

src/reference/docbook/overview.xml

@@ -108,7 +108,7 @@ TR: This section doesn't read well and I think we should try to rewrite it.-->Nu
         <caption><para>Overview of the Spring Framework</para></caption>
       </mediaobject></para>
 
-    <section>
+    <section id="overview-core-container">
       <title>Core Container</title>
 
       <para>The <link linkend="beans-introduction"><emphasis>Core
@@ -150,7 +150,7 @@ TR: This section doesn't read well and I think we should try to rewrite it.-->Nu
       aggregations.</para>
     </section>
 
-    <section>
+    <section id="overview-data-access">
       <title>Data Access/Integration</title>
 
       <para>The <emphasis>Data Access/Integration</emphasis> layer consists of
@@ -184,7 +184,7 @@ TR: This section doesn't read well and I think we should try to rewrite it.-->Nu
       Java objects)</emphasis>.</para>
     </section>
 
-    <section>
+    <section id="overview-web">
       <title>Web</title>
 
       <para>The <emphasis>Web</emphasis> layer consists of the Web,
@@ -215,7 +215,7 @@ It sounds important.--><!--TR: REVISED, PLS REVIEW.--></para>
       functionality of Web-Servlet module.<!--mirrors it in what way?--><!--TR: REVISED, PLS REVIEW. The functionality is mirrored - one for Servlets and the other for Portlets--></para>
     </section>
 
-    <section>
+    <section id="overview-aop-instrumentation">
       <title>AOP and Instrumentation</title>
 
       <para>Spring's <link
@@ -237,7 +237,7 @@ TR: OK. Added to diagram.--></para>
       certain application servers.</para>
     </section>
 
-    <section>
+    <section id="overview-testing">
       <title>Test</title>
 
       <para>The <emphasis>Test</emphasis> module supports the testing of
@@ -570,7 +570,7 @@ TR: OK. Added to diagram.--></para>
           </tgroup>
         </table></para>
 
-      <section>
+      <section id="overview-spring-dependencies">
         <title>Spring Dependencies and Depending on Spring</title>
 
         <para>Although Spring provides integration and support for a huge
@@ -590,7 +590,7 @@ TR: OK. Added to diagram.--></para>
         our samples mostly use Maven.</para>
       </section>
 
-      <section>
+      <section id="overview-maven-dependency-management">
         <title>Maven Dependency Management</title>
 
         <para>If you are using Maven for dependency management you don't even
@@ -678,7 +678,7 @@ TR: OK. Added to diagram.--></para>
         paste if you are using those tools.</para>
       </section>
 
-      <section>
+      <section id="overview-ivy-dependency-management">
         <title>Ivy Dependency Management</title>
 
         <para>If you prefer to use <ulink
@@ -726,7 +726,7 @@ TR: OK. Added to diagram.--></para>
       </section>
     </section>
 
-    <section>
+    <section id="overview-logging">
       <title>Logging</title>
 
       <para>Logging is a very important dependency for Spring because a) it is
@@ -763,7 +763,7 @@ TR: OK. Added to diagram.--></para>
       application works and logs happily to the console out of the box in most
       situations, and that's important.</para>
 
-      <section>
+      <section id="overview-not-using-commons-logging">
         <title>Not Using Commons Logging</title>
 
         <para>Unfortunately, the runtime discovery algorithm in
@@ -801,7 +801,7 @@ TR: OK. Added to diagram.--></para>
         alternative implementation of JCL using SLF4J as an example.</para>
       </section>
 
-      <section>
+      <section id="overview-logging-slf4j">
         <title>Using SLF4J</title>
       </section>
 
@@ -884,7 +884,7 @@ TR: OK. Added to diagram.--></para>
       slf4j-api dependency from other external dependencies (not Spring),
       because you only want one version of that API on the classpath.</para>
 
-      <section>
+      <section id="overview-logging-log4j">
         <title>Using Log4J</title>
 
         <para>Many people use <ulink
@@ -928,7 +928,7 @@ log4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p %t %c{2}:%L - %m
 
 log4j.category.org.springframework.beans.factory=DEBUG</programlisting>
 
-        <section>
+        <section id="overview-native-jcl">
           <title>Runtime Containers with Native JCL</title>
 
           <para>Many people run their Spring applications in a container that