Note supported platforms & versions (#586)

* Note supported platforms & versions

* Fix incorrect wording

Author: penelopeysm

getting-started/index.qmd

@@ -28,6 +28,15 @@ using Pkg
 Pkg.add("Turing")
 ```
 
+### Supported versions and platforms
+
+Formally, we only run continuous integration tests on: (1) the minimum supported minor version (typically an LTS release), and (2) the latest minor version of Julia.
+We test on Linux (x64), macOS (Apple Silicon), and Windows (x64).
+The Turing developer team will prioritise fixing issues on these platforms and versions.
+
+If you run into a problem on a different version (e.g. older patch releases) or platforms (e.g. 32-bit), please do feel free to [post an issue](https://github.com/TuringLang/Turing.jl/issues/new?template=01-bug-report.yml)!
+If we are able to help, we will try to fix it, but we cannot guarantee support for untested versions.
+
 ### Example usage
 
 First, we load the Turing and StatsPlots modules.