DATAJPA-218 - Tweaked reference documentation on Query by Example.

Fixed section anchors to match convention. Added level offsets to adapt to changes in Spring Data Commons.

Author: odrotbohm

src/main/asciidoc/jpa.adoc

@@ -604,8 +604,8 @@ List<Customer> customers = customerRepository.findAll(
 As you can see, `Specifications` offers some glue-code methods to chain and combine `Specification` instances. Thus extending your data access layer is just a matter of creating new `Specification` implementations and combining them with ones already existing.
 ====
 
-include::{spring-data-commons-docs}/query-by-example.adoc[]
-include::query-by-example.adoc[]
+include::{spring-data-commons-docs}/query-by-example.adoc[leveloffset=+1]
+include::query-by-example.adoc[leveloffset=+1]
 
 [[transactions]]
 == Transactionality

src/main/asciidoc/query-by-example.adoc

@@ -1,5 +1,5 @@
-[[query.by.example.execution]]
-== Executing Example
+[[query-by-example.execution]]
+== Executing an example
 
 In Spring Data JPA you can use Query by Example with Repositories.