message: Turn \providecommand into \newcommand for mathjax preview
  Fix
diff: @@ -22,6 +22,10 @@ export class MathPreview {
  this.mj = new MathJaxPool(extension)
  }
  + private postProcessNewCommands(commands: string): string {
  + return commands.replace(/\\providecommand/g, '\\newcommand')
  + }
  +
  private async loadNewCommandFromConfigFile(newCommandFile: string) {
  let commandsString = ''
  if (newCommandFile === '') {
  @@ -46,6 +50,7 @@ export class MathPreview {
  }
  }
  commandsString = commandsString.replace(/^\s*$/gm, '')
  + commandsString = this.postProcessNewCommands(commandsString)
  return commandsString
  }
  @@ -70,7 +75,7 @@ export class MathPreview {
  const content = this.extension.manager.cachedContent[tex].content
  commands = commands.concat(await this.findNewCommand(content))
  }
  - return commandsInConfigFile + '\n' + commands.join('')
  + return commandsInConfigFile + '\n' + this.postProcessNewCommands(commands.join(''))
  }
  private async findNewCommand(content: string): Promise<string[]> {
  