Velezbeltran patch 3 (#121)

* Add FAQ section on model speed issues

* Fix formatting in FAQ section of README

* Fix formatting in FAQ section of README

* Update FAQ with model speed improvement tips

* Update FAQ on sampling speed issues

* Correct FAQ entry on sampling speed issues

* Fix formatting issue in FAQ section of README

Author: velezbeltran

README.md

@@ -98,6 +98,10 @@ y_quantiles = y_samples.sample_quantile(q=[0.05, 0.95])
 
 See the documentation for more information on available methods and parameters.
 
+## FAQ:
+
+**Sampling Speed Issues**: Some users have reported slow sampling speeds. If this is your case, you can get significant improvements by reducing either of these two hyper-parameters: `n_estimators` or `early_stopping_rounds`.
+
 ---
 
 ## Citing Treeffuser