Fixed fragment usage and applied GQL syntax highlight (#553)

Author: lucasconstantino

doc/upgrade/beta6.md

@@ -7,7 +7,7 @@ The type structure of the `Url` object changed. While before there have been jus
 
 In a nutshell, if you were using this kind of query:
 
-```
+```gql
 query {
   route(path: "/node/1") {
     entity {
@@ -18,10 +18,10 @@ query {
 ```
 
 It has to become this:
-```
+```gql
 query {
   route(path: "/node/1") {
-    ... EntityCanonicalUrl {
+    ... on EntityCanonicalUrl {
       entity {
         entityLabel
       }
@@ -34,7 +34,7 @@ query {
 The interfaces for entities have been aligned with the entity interfaces in Drupal. There is an `EntityOwnable`, `EntityPublishable` and `EntityRevisionable` interface which now hold the respective fields.
 
 Before:
-```
+```gql
 query {
   entity:route(path: "/node/1") {
     ... on EntityCanonicalUrl {
@@ -55,7 +55,7 @@ query {
 
 After:
 
-```
+```gql
 query {
   entity:route(path: "/node/1") {
     ... on EntityCanonicalUrl {
@@ -85,35 +85,35 @@ Emumerations are uppercased now. For the schema generated by `graphql_core` this
 
 Before:
 
-```
+```gql
 query {
   entity:route(path: "/node/1") {
     ... on EntityCanonicalUrl {
       entity {
         entityTranslation(language: de) {
-	        ... on NodeArticle {
+	  ... on NodeArticle {
             entityLabel
             fieldImage {
               derivative(style: thumbnail) {
                 url
               }
             }
-  	      }
-        }
   	  }
-  	}
+        }
+      }
+    }
   }
 }
 ```
 
 After:
-```
+```gql
 query {
   entity:route(path: "/node/1") {
     ... on EntityCanonicalUrl {
       entity {
         entityTranslation(language: DE) {
-	        ... on NodeArticle {
+	  ... on NodeArticle {
             entityLabel
             fieldImage {
               derivative(style: THUMBNAIL) {
@@ -122,8 +122,8 @@ query {
             }
        	  }
         }
-  	  }
-  	}
+      }
+    }
   }
 }
 ```
@@ -132,7 +132,7 @@ query {
 Entity fields that contain only one property are simplified and directly emit that value.
 
 Before:
-```
+```gql
 ... on NodeArticle {
   fieldPlainText {
     value
@@ -141,7 +141,7 @@ Before:
 ```
 
 After:
-```
+```gql
 ... on NodeArticle {
   fieldPlainText
 }