Clarify handling of files specified in spring.config.location

Closes gh-5147

Author: wilkinsona

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

@@ -470,7 +470,11 @@ property (typically OS env, system property or command line argument).
 
 If `spring.config.location` contains directories (as opposed to files) they should end
 in `/` (and will be appended with the names generated from `spring.config.name` before
-being loaded). The default search path `classpath:,classpath:/config,file:,file:config/`
+being loaded, including profile-specific file names). Files specified in
+`spring.config.location` are used as-is, with no support for profile-specific variants,
+and will be overridden by any profile-specific properties.
+
+The default search path `classpath:,classpath:/config,file:,file:config/`
 is always used, irrespective of the value of `spring.config.location`. This search path
 is ordered from lowest to highest precedence (`file:config/` wins). If you do specify
 your own locations, they take precedence over all of the default locations and use the
@@ -506,6 +510,10 @@ If several profiles are specified, a last wins strategy applies. For example, pr
 specified by the `spring.profiles.active` property are added after those configured via
 the `SpringApplication` API and therefore take precedence.
 
+NOTE: If you have specified any files in `spring.config.location`, profile-specific
+variants of those files will not be considered. Use directories in`spring.config.location`
+if you also want to also use profile-specific properties.
+
 
 
 [[boot-features-external-config-placeholders-in-properties]]