message: not render cursor at the beginning and at the end
diff: @@ -186,7 +186,7 @@ export class HoverProvider implements vscode.HoverProvider {
  if (color !== 'auto') {
  sym = `{\\color{${color}}${symbol}}`
  }
  - if (range.contains(cursor)) {
  + if (range.contains(cursor) && !range.start.isEqual(cursor) && !range.end.isEqual(cursor)) {
  return document.getText( new vscode.Range(range.start, cursor) ) + sym + document.getText( new vscode.Range(cursor, range.end))
  }
  }
  