Document how to use WebJars without webjars-locator-core dependency

Closes gh-29322

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/WebJarsResourceResolver.java

@@ -30,8 +30,8 @@ import org.springframework.lang.Nullable;
  * attempts to find a matching versioned resource contained in a WebJar JAR file.
  *
  * <p>This allows WebJars.org users to write version agnostic paths in their templates,
- * like {@code <script src="/jquery/jquery.min.js"/>}.
- * This path will be resolved to the unique version {@code <script src="/jquery/1.2.0/jquery.min.js"/>},
+ * like {@code <script src="/webjars/jquery/jquery.min.js"/>}.
+ * This path will be resolved to the unique version {@code <script src="/webjars/jquery/1.2.0/jquery.min.js"/>},
  * which is a better fit for HTTP caching and version management in applications.
  *
  * <p>This also resolves resources for version agnostic HTTP requests {@code "GET /jquery/jquery.min.js"}.
@@ -39,6 +39,9 @@ import org.springframework.lang.Nullable;
  * <p>This resolver requires the {@code org.webjars:webjars-locator-core} library
  * on the classpath and is automatically registered if that library is present.
  *
+ * <p>Be aware that {@code WebJarAssetLocator} constructor performs a classpath scanning that
+ * could slow down application startup.
+ *
  * @author Brian Clozel
  * @since 4.2
  * @see org.springframework.web.servlet.config.annotation.ResourceChainRegistration