added make docs.

docs/index.md

@@ -45,6 +45,8 @@ NHS Notify - for the NHS Notify web site, onboarding guidance, and customer supp
 - [Table of Contents](#table-of-contents)
 - [Documentation](#documentation)
 - [Setup](#setup)
+  - [Prerequisites](#prerequisites)
+  - [Configuration](#configuration)
 - [Contributing](#contributing)
 - [Licence](#licence)
 
@@ -63,6 +65,34 @@ cd nhs-notify
 code project.code-workspace
 ```
 
+### Prerequisites
+
+The following software packages, or their equivalents, are expected to be installed and configured:
+
+- [Docker](https://www.docker.com/) container runtime or a compatible tool, e.g. [Podman](https://podman.io/),
+- [asdf](https://asdf-vm.com/) version manager,
+- [GNU make](https://www.gnu.org/software/make/) 3.82 or later,
+- [GNU coreutils](https://www.gnu.org/software/coreutils/) and [GNU binutils](https://www.gnu.org/software/binutils/) may be required to build dependencies like Python, which may need to be compiled during installation. For macOS users, this has been scripted and automated by the `dotfiles` project; please see this [script](https://github.com/nhs-england-tools/dotfiles/blob/main/assets/20-install-base-packages.macos.sh) for details,
+- [Python](https://www.python.org/) required to run Git hooks,
+- [`jq`](https://jqlang.github.io/jq/) a lightweight and flexible command-line JSON processor.
+
+> [!NOTE]<br>
+> The version of GNU make available by default on macOS is earlier than 3.82. You will need to upgrade it or certain `make` tasks will fail. On macOS, you will need [Homebrew](https://brew.sh/) installed, then to install `make`, like so:
+>
+> ```shell
+> brew install make
+> ```
+>
+> You will then see instructions to fix your `$PATH` variable to make the newly installed version available. If you are using [dotfiles](https://github.com/nhs-england-tools/dotfiles), this is all done for you.
+
+### Configuration
+
+Installation and configuration of the toolchain dependencies (including pre git hooks).
+
+```shell
+make config
+```
+
 ## Contributing
 
 Describe or link templates on how to raise an issue, feature request or make a contribution to the codebase. Reference the other documentation files, like