Fix variable name and grammar issues;

Author: bjornbytes

spec/Section 2 -- Language.md

@@ -144,7 +144,7 @@ Punctuator :: one of ! $ ( ) ... : = @ [ ] { }
 
 GraphQL documents include punctuation in order to describe structure. GraphQL
 is a data description language and not a programming language, therefore GraphQL
-lacks the punctionation often used to describe mathematical expressions.
+lacks the punctuation often used to describe mathematical expressions.
 
 
 ### Names

spec/Section 5 -- Validation.md

@@ -572,7 +572,7 @@ but this is not valid on a non-null argument.
 
 ```!graphql
 fragment missingRequiredArg on Arguments {
-  notNullBooleanArgField
+  nonNullBooleanArgField
 }
 ```
 
@@ -594,7 +594,7 @@ fragment missingRequiredArg on Arguments {
 Fragment definitions are referenced in fragment spreads by name. To avoid
 ambiguity, each fragment's name must be unique within a document.
 
-Inline fragments are not considered fragment definitions, and unaffected by this
+Inline fragments are not considered fragment definitions, and are unaffected by this
 validation rule.
 
 For example the following document is valid: