Add repositories.adoc documenting the auto-configuration of Spring Data for Apache Geode/Pivotal GemFire Repositories.

spring-geode-docs/src/docs/asciidoc/index.adoc

@@ -107,3 +107,4 @@ Finally, we arrive at Spring Boot for Apache Geode & Pivotal GemFire.
 
 include::clientcache-applications.adoc[]
 include::caching.adoc[]
+include::repositories.adoc[]

spring-geode-docs/src/docs/asciidoc/repositories.adoc

@@ -0,0 +1,88 @@
+[[geode-repositories]]
+== Spring Data for Apache Geode & Pivotal GemFire Repositories
+
+Using Spring Data Repositories with Apache Geode or Pivotal GemFire makes short work of data access operations
+when using either Apache Geode or Pivotal GemFire as your System of Record (SOR), persisting your application's
+state.
+
+{spring-data-commons-docs-html}/#repositories[Spring Data Repositories] provides a convenient and highly powerful way
+to define basic CRUD and simply query data access operations simply by specifying the contract of those data access
+operations with a Java interface.
+
+Spring Boot for Apache Geode & Pivotal GemFire _auto-configures_ the Spring Data for Apache Geode/Pivotal GemFire
+{spring-data-geode-docs-html}/#gemfire-repositories[Repository infrastructure and extension] when either is
+declared on your application's classpath.  You do not need to do anything special to enable it.  Simply start coding
+your application-specific Repository interface extensions and the way you go.
+
+For example:
+
+Define the `Customer` application domain object modeling customers and map it to the GemFire/Geode "Customers" Region
+using SDG's {spring-data-geode-javadoc}/org/springframework/data/gemfire/mapping/annotation/Region.html[`@Region`]
+mapping annotation:
+
+.Customer application domain object
+[source,java]
+----
+package example.app.model;
+
+import ...;
+@Region("Customers")
+class Customer {
+
+    @Id
+    private Long id;
+
+    private String name;
+
+    ....
+}
+----
+
+Declare your _Repository_ (Data Access Object (DAO)) for `Customers`...
+
+.CustomerRepository for peristing and accessing `Customers`
+[source,java]
+----
+package example.app.repo;
+
+import ...;
+
+interface CustomerRepository extends CrudRepository<Customer, Long> {
+
+    List<Customer> findByLastNameLikeOrderByLastNameDescFirstNameAsc(String customerLastNameWildcard);
+
+}
+----
+
+Then use the `CustomerRepository` in an application service class:
+
+.Inject and use the `CustomerRepository`
+[source,java]
+----
+package example.app;
+
+import ...;
+
+@SpringBootApplication
+@EnableEntityDefinedRegions(basePackageClasses = Customer.class)
+class SpringBootApacheGeodeClientCacheApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(SpringBootApacheGeodeClientCacheApplication.class, args);
+    }
+
+    @Bean
+    ApplicationRunner runner(CustomerRepository customerRepository) {
+
+        // Matches Williams, Wilson, etc.
+        List<Customer> customers =
+            customerRepository.findByLastNameLikeOrderByLastNameDescFirstNameAsc("Wil%");
+
+        // process the list of matching customers...
+    }
+}
+----
+
+Again, see Spring Data Commons' {spring-data-commons-docs-html}/#repositories[Repositories abstraction] in general,
+and Spring Data for Apache Geode/Pivotal GemFire {spring-data-geode-docs-html}/#gemfire-repositories[Repositories extension]
+in particular, for more details.