Merge pull request #856 from mitsu-ksgr/accept_uppercase_json

Accept the ".JSON" (uppercase) file.

src/services/storage/Validator.ts

@@ -23,7 +23,7 @@ export type ValidateKeyboardDefinitionSchemaResult = {
 };
 
 export const isJsonFile = (file: File): boolean => {
-  return file.name.endsWith('.json');
+  return file.name.toLowerCase().endsWith('.json');
 };
 
 export const validateIds = (