Add links to Spring Boot for Apache Geode and its documentation

Closes gh-29697

spring-boot-project/spring-boot-docs/src/docs/asciidoc/attributes.adoc

@@ -45,6 +45,8 @@
 :spring-boot-cli-module-api: {spring-boot-api}/org/springframework/boot/cli
 :spring-boot-devtools-module-code: {spring-boot-code}/spring-boot-project/spring-boot-devtools/src/main/java/org/springframework/boot/devtools
 :spring-boot-devtools-module-api: {spring-boot-api}/org/springframework/boot/devtools
+:spring-boot-for-apache-geode: https://github.com/spring-projects/spring-boot-data-geode
+:spring-boot-for-apache-geode-docs: https://docs.spring.io/spring-boot-data-geode-build/1.5.x/reference/html5/
 :spring-boot-test-module-code: {spring-boot-code}/spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test
 :spring-boot-test-module-api: {spring-boot-api}/org/springframework/boot/test
 :spring-boot-test-autoconfigure-module-code: {spring-boot-code}/spring-boot-project/spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure

spring-boot-project/spring-boot-docs/src/docs/asciidoc/features/caching.adoc

@@ -49,6 +49,8 @@ If you have not defined a bean of type `CacheManager` or a `CacheResolver` named
 . <<features#features.caching.provider.caffeine,Caffeine>>
 . <<features#features.caching.provider.simple,Simple>>
 
+Additionally, {spring-boot-for-apache-geode}[Spring Boot for Apache Geode] provides {spring-boot-for-apache-geode-docs}#geode-caching-provider[auto-configuration for using Apache Geode as a cache provider].
+
 TIP: It is also possible to _force_ a particular cache provider by setting the configprop:spring.cache.type[] property.
 Use this property if you need to <<features#features.caching.provider.none,disable caching altogether>> in certain environment (such as tests).
 

spring-boot-project/spring-boot-docs/src/docs/asciidoc/features/nosql.adoc

@@ -12,6 +12,7 @@ Spring Data provides additional projects that help you access a variety of NoSQL
 * {spring-data-ldap}[LDAP]
 
 Spring Boot provides auto-configuration for Redis, MongoDB, Neo4j, Solr, Elasticsearch, Cassandra, Couchbase, LDAP and InfluxDB.
+Additionally, {spring-boot-for-apache-geode}[Spring Boot for Apache Geode] provides {spring-boot-for-apache-geode-docs}#geode-repositories[auto-configuration for Apache Geode].
 You can make use of the other projects, but you must configure them yourself.
 Refer to the appropriate reference documentation at {spring-data}.
 

spring-boot-project/spring-boot-docs/src/docs/asciidoc/features/spring-session.adoc

@@ -8,6 +8,8 @@ When building a Servlet web application, the following stores can be auto-config
 * Hazelcast
 * MongoDB
 
+Additionally, {spring-boot-for-apache-geode}[Spring Boot for Apache Geode] provides {spring-boot-for-apache-geode-docs}#geode-session[auto-configuration for using Apache Geode as a session store].
+
 The Servlet auto-configuration replaces the need to use `@Enable*HttpSession`.
 
 When building a reactive web application, the following stores can be auto-configured: