update readme

Author: rpreen

README.md

@@ -25,6 +25,8 @@ Additional programming languages such as this R package are supported by providi
 
 ### Installation
 
+Prerequisite: you must have [Python](https://www.python.org) pre-installed.
+
 Install the **acro** package from CRAN as follows:
 
 ``` r
@@ -44,7 +46,9 @@ Before using any function from the package, an acro object should be initialised
 
 ### Try Online with MyBinder
 
-Try an example notebook in RStudio online on [MyBinder.org](https://mybinder.org/v2/gh/AI-SDC/ACRO-R/main?urlpath=rstudio). Select the `example-notebook.Rmd` in the bottom-right pane after loading.
+Try an example notebook in RStudio online on [MyBinder.org](https://mybinder.org/v2/gh/AI-SDC/ACRO-R/main?urlpath=rstudio).
+
+Select the `example-notebook.Rmd` in the bottom-right pane after loading.
 
 ### Documentation