Fix typos in AutoConfigureRestDocs

Closes gh-10810

Author: dreis2211

spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/restdocs/AutoConfigureRestDocs.java

@@ -49,15 +49,15 @@
 public @interface AutoConfigureRestDocs {
 
 	/**
-	 * The output directory to which generated snippets will be written. A alias for
+	 * The output directory to which generated snippets will be written. An alias for
 	 * {@link #outputDir}.
 	 * @return the output directory
 	 */
 	@AliasFor("outputDir")
 	String value() default "";
 
 	/**
-	 * The output directory to which generated snippets will be written. A alias for
+	 * The output directory to which generated snippets will be written. An alias for
 	 * {@link #value}.
 	 * @return the output directory
 	 */