Add JavaDoc for health-check request handling

Added JavaDoc comment for the doGet method in HealthServlet.

Author: ArchILLtect

src/main/java/me/nickhanson/codeforge/web/HealthServlet.java

@@ -15,6 +15,14 @@
 @WebServlet(urlPatterns = {"/health"})
 public class HealthServlet extends HttpServlet {
 
+    /**
+     * Handles health-check requests by returning an immediate {@code 200 OK}
+     * response with a plain-text {@code OK} body.
+     *
+     * @param req  the incoming HTTP request
+     * @param resp the HTTP response used to return health status
+     * @throws IOException if writing the response fails
+     */
     @Override
     protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
         resp.setStatus(HttpServletResponse.SC_OK);