initial changes

Author: twof

spec/Appendix B -- Grammar Summary.md

@@ -45,7 +45,7 @@ Token ::
   - FloatValue
   - StringValue
 
-Punctuator :: one of ! $ & ( ) ... : = @ [ ] { | }
+Punctuator :: one of ! ? $ & ( ) ... : = @ [ ] { | }
 
 Name ::
   - NameStart NameContinue* [lookahead != NameContinue]

spec/Section 7 -- Response.md

@@ -161,10 +161,11 @@ The response might look like:
 }
 ```
 
-If the field which experienced an error was declared as `Non-Null`, the `null`
-result will bubble up to the next nullable field. In that case, the `path`
-for the error should include the full path to the result field where the error
-was raised, even if that field is not present in the response.
+If the field which experienced an error was declared as `Non-Null` or marked
+`Non-Null` in the query document, the `null` result will bubble up to the 
+next nullable field. In that case, the `path` for the error should include
+the full path to the result field where the error was raised, even if that
+field is not present in the response.
 
 For example, if the `name` field from above had declared a `Non-Null` return
 type in the schema, the result would look different but the error reported would