message: Only handle mutliline $$...$$ not $...$
diff: @@ -178,12 +178,16 @@ export class CodeActions {
  const regex = new RegExp('^' + oldDelim.replace(/\$/g, '\\$') + '$')
  const regexResult = regex.exec(text)
  if (!regexResult) {
  + if (oldDelim === '$$') {
  const pat = new RegExp(oldDelim.replace(/\$/g, '\\$') + '(?!\\$)')
  const endPos = this.extension.mathPreview.texMathEnvFinder.findEndPair(document, pat, endRange.start)
  if (!endPos) {
  return
  }
  endRange = new vs.Range(endPos.translate(0, - oldDelimLength), endPos)
  + } else {
  + return
  + }
  }
  const edit = new vs.WorkspaceEdit()
  edit.replace(document.uri, endRange, endDelim)
  