Port "how-to" section to the reference manual

Copy the existing markdown How-to readme content to the user manual,
converting to asciidoc.

See gh-295

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

@@ -291,7 +291,8 @@ properties).
 ----
 
 TIP: You can also use this technique to create ``short'' variants of existing Spring Boot
-properties.
+properties. See the ``<<howto.adoc#howto-use-short-command-line-arguments>>'' how-to
+for details.