Add javadoc

Author: NSeydoux

api/src/main/java/com/inrupt/client/ClientHttpException.java

@@ -20,6 +20,10 @@
  */
 package com.inrupt.client;
 
+/**
+ * A runtime exception representing an HTTP error response carrying a structured representation of the problem. The
+ * problem description is embedded in a {@link ProblemDetails} instance.
+ */
 public class ClientHttpException extends InruptClientException {
     private final ProblemDetails problemDetails;
 

api/src/main/java/com/inrupt/client/ProblemDetails.java

@@ -22,6 +22,11 @@
 
 import java.net.URI;
 
+/**
+ * A data class representing a structured problem description sent by the server on error response.
+ *
+ * @see <a href="https://www.rfc-editor.org/rfc/rfc9457">RFC 9457 Problem Details for HTTP APIs</a>
+ */
 public class ProblemDetails {
     public static final String MIME_TYPE = "application/problem+json";
     public static final String DEFAULT_TYPE = "about:blank";