docs: Fix REQ command operator usage example

api/envoy/config/core/v3/substitution_format_string.proto

@@ -23,15 +23,17 @@ message SubstitutionFormatString {
     // Specify a format with command operators to form a text string.
     // Its details is described in :ref:`format string<config_access_log_format_strings>`.
     //
-    // .. code-block::
+    // For example, setting ``text_format`` like below,
     //
-    //   text_format: %LOCAL_REPLY_BODY%:%RESPONSE_CODE%:path=$REQ(:path)%
+    // .. code-block:: yaml
     //
-    // The following plain text will be created:
+    //   text_format: "%LOCAL_REPLY_BODY%:%RESPONSE_CODE%:path=%REQ(:path)%\n"
     //
-    // .. code-block::
+    // generates plain text similar to:
     //
-    //   upstream connect error:204:path=/foo
+    // .. code-block:: text
+    //
+    //   upstream connect error:503:path=/foo
     //
     string text_format = 1 [(validate.rules).string = {min_bytes: 1}];
 
@@ -41,11 +43,11 @@ message SubstitutionFormatString {
     // Nested JSON objects may be produced by some command operators (e.g. FILTER_STATE or DYNAMIC_METADATA).
     // See the documentation for a specific command operator for details.
     //
-    // .. code-block::
+    // .. code-block:: yaml
     //
     //  json_format:
-    //    status: %RESPONSE_CODE%
-    //    message: %LOCAL_REPLY_BODY%
+    //    status: "%RESPONSE_CODE%"
+    //    message: "%LOCAL_REPLY_BODY%"
     //
     // The following JSON object would be created:
     //
@@ -70,7 +72,7 @@ message SubstitutionFormatString {
   // If this field is not set then ``text/plain`` is used for *text_format* and
   // ``application/json`` is used for *json_format*.
   //
-  // .. code-block::
+  // .. code-block:: yaml
   //
   //   content_type: "text/html; charset=UTF-8"
   //

api/envoy/extensions/filters/network/http_connection_manager/v3/http_connection_manager.proto

@@ -571,27 +571,27 @@ message LocalReplyConfig {
   // The configuration to form response body from the :ref:`command operators <config_access_log_command_operators>`
   // and to specify response content type as one of: plain/text or application/json.
   //
-  // Example one: plain/text body_format.
+  // Example one: "plain/text" ``body_format``.
   //
-  // .. code-block::
+  // .. code-block:: yaml
   //
-  //   text_format: %LOCAL_REPLY_BODY%:%RESPONSE_CODE%:path=$REQ(:path)%
+  //   text_format: "%LOCAL_REPLY_BODY%:%RESPONSE_CODE%:path=%REQ(:path)%\n"
   //
-  // The following response body in `plain/text` format will be generated for a request with
+  // The following response body in "plain/text" format will be generated for a request with
   // local reply body of "upstream connection error", response_code=503 and path=/foo.
   //
-  // .. code-block::
+  // .. code-block:: text
   //
   //   upstream connect error:503:path=/foo
   //
-  //  Example two: application/json body_format.
+  // Example two: "application/json" ``body_format``.
   //
-  // .. code-block::
+  // .. code-block:: yaml
   //
   //  json_format:
-  //    status: %RESPONSE_CODE%
-  //    message: %LOCAL_REPLY_BODY%
-  //    path: $REQ(:path)%
+  //    status: "%RESPONSE_CODE%"
+  //    message: "%LOCAL_REPLY_BODY%"
+  //    path: "$REQ(:path)%"
   //
   // The following response body in "application/json" format would be generated for a request with
   // local reply body of "upstream connection error", response_code=503 and path=/foo.