Add more anchor redirects

See gh-43367

Author: philwebb

spring-boot-project/spring-boot-docs/src/docs/antora/modules/ROOT/pages/redirect.adoc

@@ -24,7 +24,9 @@
 * xref:specification:executable-jar/index.adoc[executable-jar]
 * xref:appendix:dependency-versions/index.adoc[dependency-versions]
 * xref:community.adoc[#getting-help]
+* xref:community.adoc[#documentation.getting-help]
 * xref:documentation.adoc[#documentation]
+* xref:documentation.adoc[#documentation.about]
 * xref:index.adoc[#getting-started]
 * xref:upgrading.adoc[#upgrading]
 * xref:reference:using/index.adoc#using[#using]
@@ -1615,3 +1617,11 @@
 * xref:tutorial:first-application/index.adoc#getting-started.first-application.run[#getting-started.first-application.run]
 * xref:tutorial:first-application/index.adoc#getting-started.first-application.run.gradle[#getting-started.first-application.run.gradle]
 * xref:tutorial:first-application/index.adoc#getting-started.first-application.run.maven[#getting-started.first-application.run.maven]
+* xref:reference:io/caching.adoc#io.caching.provider.jcache[#features.caching.provider.ehcache2]
+* xref:reference:features/external-config.adoc#features.external-config.files.importing-extensionless[#features.external-config.file.importing-extensionless]
+* xref:reference:using/build-systems.adoc#using.build-systems.maven[#build-tool-plugins.maven]
+* xref:reference:using/build-systems.adoc#using.build-systems.gradle[#build-tool-plugins.gradle]
+* xref:reference:messaging/amqp.adoc#messaging.amqp.rabbitmq[#messaging.amqp.rabbit]
+* xref:reference:data/nosql.adoc#data.nosql.elasticsearch.connecting-using-rest[#data.nosql.elasticsearch.connecting-using-reactive-rest]
+* xref:index.adoc[#getting-started.introducing-spring-boot]
+* xref:index.adoc[#spring-boot-reference-documentation]