message: Do not use multiline regex flag when checking a single line
diff: @@ -251,7 +251,7 @@ class StructureModel {
  }
  buildEnvModel(envNames: string[], lines: string[], lineNumber: number) {
  - const envReg = RegExp(`(?:\\\\(begin|end)(?:\\[[^[\\]]*\\])?){(?:(${envNames.join('|')})\\*?)}`, 'm')
  + const envReg = RegExp(`(?:\\\\(begin|end)(?:\\[[^[\\]]*\\])?){(?:(${envNames.join('|')})\\*?)}`)
  const line = lines[lineNumber]
  const result = envReg.exec(line)
  if (result && result[1] === 'begin') {
  @@ -302,7 +302,7 @@ class StructureModel {
  if (commandNames.length === 0) {
  return
  }
  - const commandReg = new RegExp('\\\\(' + commandNames.join('|') + '){([^}]*)}', 'm' )
  + const commandReg = new RegExp('\\\\(' + commandNames.join('|') + '){([^}]*)}')
  const result = commandReg.exec(line)
  if (!result) {
  return
  @@ -318,7 +318,7 @@ class StructureModel {
  buildHeadingModel(lines: string[], lineNumber: number, showNumbers: boolean) {
  const line = lines[lineNumber]
  - const headerReg = RegExp(this.headerPattern, 'm')
  + const headerReg = RegExp(this.headerPattern)
  const result = headerReg.exec(line)
  if (!result) {
  return
  