Update docs

Author: mdmintz

help_docs/features_list.md

@@ -1,11 +1,12 @@
 <a id="feature_list"></a>
-### ![http://seleniumbase.com](https://cdn2.hubspot.net/hubfs/100006/images/super_logo_tiny.png "SeleniumBase") **SeleniumBase Features:**
+## <img src="https://cdn2.hubspot.net/hubfs/100006/images/super_square_logo_3a.png" title="SeleniumBase" height="32"> **SeleniumBase Features:**
 * A complete test automation framework for building & running reliable testing scripts.
 * Uses [Pytest](https://docs.pytest.org/en/latest/) and [Nose](http://nose.readthedocs.io/en/latest/) runners for test discovery, organization, execution, and logging.
 * Includes [console scripts](https://github.com/seleniumbase/SeleniumBase/blob/master/seleniumbase/console_scripts/ReadMe.md) that save you time by installing web drivers automatically, etc. 
 * Includes a [website tour builder](https://github.com/seleniumbase/SeleniumBase/blob/master/examples/tour_examples/ReadMe.md) for creating and running walkthroughs on any website.
 * Works on multiple platforms such as macOS, Windows, Linux, and [Docker](https://github.com/seleniumbase/SeleniumBase/blob/master/integrations/docker/ReadMe.md).
 * Uses a [flexible command-line interface](https://github.com/seleniumbase/SeleniumBase/blob/master/help_docs/customizing_test_runs.md) to customize & configure test runs.
+* Can run tests using multiple concurrent threads. (Use ``-n THREAD_COUNT``)
 * Has Python libraries for helping you do much more with Selenium/WebDriver.
 * Has [Plugins](https://github.com/seleniumbase/SeleniumBase/tree/master/seleniumbase/plugins) for logging data and screenshots automatically. ([Click to learn more](https://github.com/seleniumbase/SeleniumBase/blob/master/examples/example_logs/ReadMe.md))
 * Uses a [global config file](https://github.com/seleniumbase/SeleniumBase/blob/master/seleniumbase/config/settings.py) for configuring SeleniumBase to your specific needs.