Polish "Background Initialization" documentation

Author: sbrannen

framework-docs/modules/ROOT/pages/core/beans/java/composing-configuration-classes.adoc

@@ -522,23 +522,28 @@ allows for singling out specific beans for background initialization, covering t
 entire bean creation step for each such bean on context startup.
 
 Dependent beans with non-lazy injection points automatically wait for the bean instance
-to be completed. All regular background initializations are forced to complete at the
-end of context startup. Only for beans additionally marked as `@Lazy`, the completion
-is allowed to happen later (up until first actual access).
+to be completed. All regular background initializations are forced to complete at the end
+of context startup. Only beans additionally marked as `@Lazy` are allowed to be completed
+later (up until the first actual access).
 
 Background initialization typically goes together with `@Lazy` (or `ObjectProvider`)
 injection points in dependent beans. Otherwise, the main bootstrap thread is going to
 block when an actual background-initialized bean instance needs to be injected early.
 
-This form of concurrent startup applies to individual beans: If such a bean depends on
+This form of concurrent startup applies to individual beans: if such a bean depends on
 other beans, they need to have been initialized already, either simply through being
-declared earlier or through `@DependsOn` which is enforcing initialization in the main
+declared earlier or through `@DependsOn` which enforces initialization in the main
 bootstrap thread before background initialization for the affected bean is triggered.
 
-Note that a `bootstrapExecutor` bean of type `Executor` needs to be declared for
-background bootstrapping to be actually active. Otherwise, the background markers are
-going to be ignored at runtime. The bootstrap executor may be a bounded executor just
-for startup purposes or a shared thread pool which serves for other purposes as well.
+[NOTE]
+====
+A `bootstrapExecutor` bean of type `Executor` must be declared for background
+bootstrapping to be actually active. Otherwise, the background markers will be ignored at
+runtime.
+
+The bootstrap executor may be a bounded executor just for startup purposes or a shared
+thread pool which serves for other purposes as well.
+====
 
 
 [[beans-java-conditional]]