DATACMNS-1814 - Fixes missing anchors.

Fixes the problem of the "Using filters" link jumping to the top of
the document. There was another of these ("Configuration") later in
the document, and this commit fixes that one, too.

Original pull request: #470.

Author: Jay Bryant

src/main/asciidoc/repositories.adoc

@@ -755,6 +755,7 @@ Each bean is registered under a bean name that is derived from the interface nam
 Bean names for nested repository interfaces are prefixed with their enclosing type name.
 The `base-package` attribute allows wildcards so that you can define a pattern of scanned packages.
 
+[[repositories.using-filters]]
 ==== Using filters
 By default, the infrastructure picks up every interface extending the persistence technology-specific `Repository` sub-interface located under the configured base package and creates a bean instance for it.
 However, you might want more fine-grained control over which interfaces have bean instances created for them.
@@ -952,6 +953,7 @@ interface PersonRepository extends CrudRepository<Person, Long>, CustomizedSave<
 ----
 ====
 
+[[repositories.configuration]]
 ==== Configuration
 If you use namespace configuration, the repository infrastructure tries to autodetect custom implementation fragments by scanning for classes below the package in which it found a repository. These classes need to follow the naming convention of appending the namespace element's `repository-impl-postfix` attribute to the fragment interface name. This postfix defaults to `Impl`. The following example shows a repository that uses the default postfix and a repository that sets a custom value for the postfix: