doc: add details about various elements (Debian version, prog. lang. install)

README.md

@@ -8,18 +8,23 @@ versions of Virtual Box don't really work for nested virtualization.
 Features
 --------
 
-This VM includes the following features:
+This VM is based on Debian 12. It includes the following features:
   * a pair of networks which can be used to host virtual machines,
   * a Bind DNS server that can serve a local zone as well as reverse zones for
-    both networks, with a key that can be used to update the zones using
-    Terraform,
+    both networks, with a key that can be used to update the zones (e.g. using
+    Terraform),
   * a local resolver configuration that will forward to either the local Bind
     server (for queries on the local zones) or to the host (for other queries),
   * Docker and libvirt,
   * a full XFCE environment with Firefox, Remmina, KeepassXC and LibreOffice
     installed,
   * various IaC tools: Terraform, Terragrunt and Ansible,
-  * various programming languages: Rust, Golang, Node and Java,
+  * various programming languages:
+    * Rust (installed using [Rustup](https://rustup.rs/),
+    * Golang (installed using [ASDF](https://asdf-vm.com),
+    * Node (installed using ASDF),
+    * Java (installed using ASDF),
+    * Python (installed using [pyenv](https://github.com/pyenv/pyenv),
   * the ability to use [Chezmoi](https://www.chezmoi.io/) to import various dot
     files at provisioning time,
   * a semi-decent ZSH configuration as well as my