Automatic README update (#709)

Co-authored-by: sbfnk <[email protected]>

README.md

@@ -146,13 +146,20 @@ if (!require("remotes")) {
 remotes::install_github("epiforecasts/EpiNow2")
 ```
 
-Windows users will need a working installation of Rtools in order to
-build the package from source. See
-[here](https://github.com/stan-dev/rstan/wiki/RStan-Getting-Started#checking-the-c-toolchain)
-for a guide to installing Rtools for use with Stan (which is the
-statistical modelling platform used for the underlying model). For
-simple deployment/development a prebuilt docker image is also available
-(see documentation
+To build `{EpiNow2}` from source, users will need to configure their C
+toolchain. This is because `{EpiNow2}` implements the underlying models
+in Stan (a statistical modelling programming language), which is built
+on C++.
+
+Each operating system has a different set up procedure. Windows users
+need to install an appropriate version of
+[RTools](https://github.com/stan-dev/rstan/wiki/Configuring-C---Toolchain-for-Windows).
+Mac users can [follow these
+steps](https://github.com/stan-dev/rstan/wiki/Configuring-C---Toolchain-for-Mac),
+and Linux users can use [this
+guide](https://github.com/stan-dev/rstan/wiki/Configuring-C-Toolchain-for-Linux).
+For simple deployment/development a prebuilt docker image is also
+available (see documentation
 [here](https://github.com/epiforecasts/EpiNow2/wiki/Docker)).
 
 ## Resources