Fix typo in xml attribute name.

Author: someone-with-default-username

Diff for: Installer/NitraGlobalConfig.xml

@@ -15,13 +15,13 @@
   </SpanClasses>
 
   <Languages>
-    <Language Name="Nitra" FileExtentions=".nitra" Grammar="NitraSyntax" StartRule="Start">
+    <Language Name="Nitra" FileExtensions=".nitra" Grammar="NitraSyntax" StartRule="Start">
       <Module>$NitraPath\Nitra.Grammar.dll</Module>
     </Language>
-    <Language Name="C#" FileExtentions=".csn" Grammar="CSharp" StartRule="CompilationUnit">
+    <Language Name="C#" FileExtensions=".csn" Grammar="CSharp" StartRule="CompilationUnit">
       <Module>$NitraPath\CSharp.Grammar.dll</Module>
     </Language>
-    <Language Name="JSON" FileExtentions=".json" Grammar="Nitra.Tests.JsonParser" StartRule="Start">
+    <Language Name="JSON" FileExtensions=".json" Grammar="Nitra.Tests.JsonParser" StartRule="Start">
       <Module>$NitraPath\Json.Grammar.dll</Module>
     </Language>
   </Languages>

Diff for: NitraGlobalConfig.xml

@@ -17,13 +17,13 @@
   </SpanClasses>
 
   <Languages>
-    <Language Name="C#" FileExtentions=".csn" Grammar="CSharp" StartRule="CompilationUnit">
+    <Language Name="C#" FileExtensions=".csn" Grammar="CSharp" StartRule="CompilationUnit">
       <Module>$NitraSamplesBinPath\CSharp.Grammar.dll</Module>
     </Language>
-    <Language Name="JSON" FileExtentions=".json" Grammar="Nitra.Tests.JsonParser" StartRule="Start">
+    <Language Name="JSON" FileExtensions=".json" Grammar="Nitra.Tests.JsonParser" StartRule="Start">
       <Module>$NitraSamplesBinPath\Json.Grammar.dll</Module>
     </Language>
-    <Language Name="Nitra" FileExtentions=".nitra" Grammar="NitraSyntax" StartRule="Start">
+    <Language Name="Nitra" FileExtensions=".nitra" Grammar="NitraSyntax" StartRule="Start">
       <Module>$NitraBinPath\Stage2\Nitra.Grammar.dll</Module>
     </Language>
   </Languages>

Diff for: VisualStudioExtensions/Nitra.VisualStudio/Languages/Language.n

@@ -20,7 +20,7 @@ namespace Nitra.VisualStudio
   {
     public Name           : string       { get; }
     public ContentType    : IContentType { get; }
-    public FileExtentions : list[string] { get; }
+    public FileExtensions : list[string] { get; }
     public Grammar        : string       { get; }
     public StartRule      : string       { get; }
     public Modules        : list[string] { get; }

Diff for: VisualStudioExtensions/Nitra.VisualStudio/Languages/NitraGlobalConfig.n

@@ -93,7 +93,7 @@ namespace Nitra.VisualStudio
         {
           def name           = lang.Attribute("Name").Value;
           def oldContentType = contentTypeRegistryService.GetContentType(name);
-          def fileExtentions = lang.Attribute("FileExtentions")?.Value?.SplitToList(';').RevMap(s => s.Trim().ToLowerInvariant());
+          def fileExtentions = lang.Attribute("FileExtensions")?.Value?.SplitToList(';').RevMap(s => s.Trim().ToLowerInvariant());
 
           when (oldContentType != null) // remove if exists
           {