Fix Asciidoc syntax

spring-boot-project/spring-boot-docs/src/main/asciidoc/howto.adoc

@@ -107,7 +107,7 @@ A custom implementation may define another order.
 
 CAUTION: While using `@PropertySource` on your `@SpringBootApplication` may seem to be a convenient way to load a custom resource in the `Environment`, we do not recommend it.
 Such property sources are not added to the `Environment` until the application context is being refreshed.
-This is too late to configure certain properties such as `logging.*` and `spring.main.*` which are read before refresh begins.
+This is too late to configure certain properties such as `+logging.*+` and `+spring.main.*+` which are read before refresh begins.
 
 
 

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

@@ -353,7 +353,7 @@ Properties are considered in the following order:
 . Application properties packaged inside your jar (`application.properties` and YAML variants).
 . {spring-framework-api}/context/annotation/PropertySource.html[`@PropertySource`] annotations on your `@Configuration` classes.
   Please note that such property sources are not added to the `Environment` until the application context is being refreshed.
-  This is too late to configure certain properties such as `logging.*` and `spring.main.*` which are read before refresh begins.
+  This is too late to configure certain properties such as `+logging.*+` and `+spring.main.*+` which are read before refresh begins.
 . Default properties (specified by setting `SpringApplication.setDefaultProperties`).
 
 To provide a concrete example, suppose you develop a `@Component` that uses a `name` property, as shown in the following example: