Update docs

README.md

@@ -38,20 +38,44 @@ or as a package from your GNU/Linux distribution.
 10. When at the login screen, ensure you are using the `Xfce Session` (settings wheel, bottom right) before entering your password.
 11. Pro-tip: User experience may be better in fullscreen (`F8` and select `fullscreen`)
 
-## Using Environmental Cheminformatics Programs
+## Using Environmental Cheminformatics programs
+
+### Getting started with Shinyscreen
+
+Shinyscreen is ECI's mass spectrum inspection program. It was written
+in R and exists as a R package. In order to run it, it is necessary to
+start a R session. 
+
+While most students get to know R through R Studio, this development
+environment (DE) is by no means the only one that can run R (indeed,
+you do not even need a DE to run R: try it yourself, start a command
+console and type `R` in there). The default choice of R DE on
+`alien-one` currently is GNU Emacs with its *Emacs Speaks Statistics
+(ESS)* mode.
+
+Steps:
 
-### Getting started
 1. Fire up emacs
 2. `Alt-x` and `R` gets you an R session
 3. Enter `library(shinyscreen)`
 4. Enter `options(browser="chromium")`
 5. Enter `launch()` 
 
-### JustInCase - Downloading instructions
+
+Alternatively, there there are two icons on your desktop that will
+start Shinyscreen immediately without a R session. One starts the
+stable version of Shinyscreen (used in this course). The other runs a
+development version (you can try it out if you feel adventurous).
+
+
+### Material needed for the practical
+
+The *mzML* data files are in `/mnt/exchange` directory.
+
+#### Just in case
 1. Raw files `*.mzML` can be downloaded from [here](https://zenodo.org/record/3666069) 
 2. Input files for Shinyscreen from [here](https://git-r3lab.uni.lu/eci/isb401/-/tree/master/shinyscreen_files)
 
-### The Rest
-TODO
+