Document packageManager

README.md

@@ -34,6 +34,7 @@ See [editor support](#editor-support) for more detailed setup instructions.
  * `alwaysShowRuleFailuresAsWarnings` - Always show rule failures as warnings, ignoring the severity configuration in the tslint.json configuration. Default is `true`.
  * `suppressWhileTypeErrorsPresent` - Suppress tslint errors from being reported while other errors are present.
  * `exclude` - List of files to exclude from tslint.
+ * `packageManager` - Package manager used, either: `npm`, `yarn`, or `pnpm`. This is currently only used for error message instructions about how to install tslint. Default is `npm`.
 
 Here is a configuration sample: