Update parametereditor.md (#1662)

Author: todorarabadzhiev

embedding-reports/display-reports-in-applications/web-application/html5-report-viewer/api-reference/parametereditor.md

@@ -23,6 +23,8 @@ table th:nth-of-type(2) {
 | Parameter | Description |
 | ------ | ------ |
 | __beginEdit(parameter)__ |creates the editor UI and populates it with the parameter settings<ul><li>parameter</li></ul>|
+| __addAccessibility(parameter)__ |adds accessibility to the parameter editor and populates its string resources<ul><li>parameter</li></ul>|
+| __setAccessibilityErrorState(parameter)__ |sets the error state of the parameter editor's accessibility functionality and its error attributes<ul><li>parameter</li></ul>|
 
 ## See Also