make a minor help change

Author: briantoby

MDhelp/docs/preface.md

@@ -4,17 +4,17 @@
 <a name="Tutorials"></a>
 
 The best way to learn about how different sections of GSAS-II is used
-is to work through some of the tutorials. The tutorials are best
-accessed through the Help/Tutorials menu command, as once a tutorial
-has been selected, that will both open the tutorial instructions in a web browser and will 
+is to work through some of the tutorials. The best way to access the
+tutorials is through the **Help/Tutorials** menu command, because once a tutorial
+has been selected, this will both open the tutorial instructions in a web browser and will 
 download any input files needed to run the tutorial. 
 It is also possible to access the tutorials via a [separate web
 page](https://advancedphotonsource.github.io/GSAS-II-tutorials/tutorials.html). 
 
 Each tutorial demonstrates a different aspect of GSAS-II; when significant new
 capabilities are added to GSAS-II it is common to create a new
-tutorial. Since
+tutorial. Note that 
 it is unlikely that any one person will use all the features of
-GSAS-II, it is not necessary to use all of them. New users are
+GSAS-II, so it is not necessary to run through all of them. New users are
 suggested to look at some of the introductory tutorials and then pick
 more advanced topics as needs arise.