Merge DynamicJsonDocument with JsonDocument

extras/scripts/wandbox/JsonGeneratorExample.cpp

@@ -13,7 +13,7 @@ int main() {
   // Inside the parentheses, 200 is the RAM allocated to this document.
   // Don't forget to change this value to match your requirement.
   // Use https://arduinojson.org/v6/assistant to compute the capacity.
-  DynamicJsonDocument doc(200);
+  JsonDocument doc(200);
 
   // Add values in the document
   //

extras/scripts/wandbox/JsonParserExample.cpp

@@ -13,7 +13,7 @@ int main() {
   // Inside the parentheses, 200 is the capacity of the memory pool in bytes.
   // Don't forget to change this value to match your JSON document.
   // Use https://arduinojson.org/v6/assistant to compute the capacity.
-  DynamicJsonDocument doc(300);
+  JsonDocument doc(300);
 
   // JSON input string.
   //

extras/scripts/wandbox/MsgPackParserExample.cpp

@@ -13,7 +13,7 @@ int main() {
   // Inside the parentheses, 300 is the size of the memory pool in bytes.
   // Don't forget to change this value to match your JSON document.
   // Use https://arduinojson.org/assistant to compute the capacity.
-  DynamicJsonDocument doc(300);
+  JsonDocument doc(300);
 
   // MessagePack input string.
   //