docs(course): expanded and polished description of course

docs/content/docs/course_intro.md

@@ -1,8 +1,21 @@
 # Introductory course
 
-We have a 2h introduction course on trame that let you dive into its core and how you can leverage trame for your own workflow.
+For those who wish to know more about the internals of trame, this developers
+course consists of a two-hour training video, as well as associated course
+slides, exercises, and a compact reference document.  This course was
+originally presented to a group of Kitware developers, and is now available
+to anyone who wishes to fully leverage trame’s powerful capabilities.
+
+The course describes trame’s architecture; guidance on how to set up a Python
+virtual environment for trame; various ways to work with internal state,
+event, ui, and widgets; approaches to working with VTK.js, VTK, and ParaView
+including VTK’s data processing pipelines along with client-side and
+server-side rendering; interfaces to the Python and Jupyter ecosystems; and
+ways to deploy trame as a desktop application or in the cloud.
+
+Please view the following assets to participate in the course.
 
 - [Video recording](https://vimeo.com/761096621/af2287747f)
 - [Slides](https://github.com/Kitware/trame-tutorial/raw/master/course/introduction/Introduction_to_trame.pdf)
 - [Exercises / code samples](https://github.com/Kitware/trame-tutorial/raw/master/course/introduction/exercises.zip)
-- [Short reference to keep](https://github.com/Kitware/trame-tutorial/raw/master/course/introduction/trame_intro_ref.pdf)
+- [Reference information](https://github.com/Kitware/trame-tutorial/raw/master/course/introduction/trame_intro_ref.pdf)