Add Javadoc for use of regexp PathPattern

Closes gh-31886

spring-web/src/main/java/org/springframework/web/util/pattern/PathPattern.java

@@ -43,7 +43,8 @@ import org.springframework.util.StringUtils;
  * <li>{@code *} matches zero or more characters within a path segment</li>
  * <li>{@code **} matches zero or more <em>path segments</em> until the end of the path</li>
  * <li><code>{spring}</code> matches a <em>path segment</em> and captures it as a variable named "spring"</li>
- * <li><code>{spring:[a-z]+}</code> matches the regexp {@code [a-z]+} as a path variable named "spring"</li>
+ * <li><code>{spring:[a-z]+}</code> matches the regexp {@code [a-z]+} against a path segment
+ * and captures it a path variable named "spring"</li>
  * <li><code>{*spring}</code> matches zero or more <em>path segments</em> until the end of the path
  * and captures it as a variable named "spring"</li>
  * </ul>