Add sed and grep to the list of prerequisites (nhs-england-tools#150)

## Description

Add `sed` and `grep` GNU toolchain commands to the list of
prerequisites.

## Context

While setting up workstations with a new team, some scripts failed and
it wasn't immediately apparent that the version of the `sed` command had
to be GNU compliant.

## Type of changes

- [x] Refactoring (non-breaking change)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would change existing
functionality)
- [ ] Bug fix (non-breaking change which fixes an issue)

## Checklist

- [x] I am familiar with the [contributing
guidelines](../docs/CONTRIBUTING.md)
- [x] I have followed the code style of the project
- [ ] I have added tests to cover my changes
- [x] I have updated the documentation accordingly
- [ ] This PR is a result of pair or mob programming

---

## Sensitive Information Declaration

To ensure the utmost confidentiality and protect your and others
privacy, we kindly ask you to NOT including [PII (Personal Identifiable
Information) / PID (Personal Identifiable
Data)](https://digital.nhs.uk/data-and-information/keeping-data-safe-and-benefitting-the-public)
or any other sensitive data in this PR (Pull Request) and the codebase
changes. We will remove any PR that do contain any sensitive
information. We really appreciate your cooperation in this matter.

- [x] I confirm that neither PII/PID nor sensitive data are included in
this PR and the codebase changes.

README.md

@@ -48,9 +48,6 @@ The following software packages, or their equivalents, are expected to be instal
 - [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:
@@ -59,7 +56,16 @@ The following software packages, or their equivalents, are expected to be instal
 > brew install make
 > ```
 >
-> You will then see instructions to fix your `$PATH` variable to make the newly installed version available. If you are using [dotfiles](https://github.com/nhs-england-tools/dotfiles), this is all done for you.
+> You will then see instructions to fix your [`$PATH`](https://github.com/nhs-england-tools/dotfiles/blob/main/dot_path.tmpl) 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.
+
+- [GNU sed](https://www.gnu.org/software/sed/) and [GNU grep](https://www.gnu.org/software/grep/) are required for the scripted command-line output processing,
+- [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,
+
+> [!NOTE]<br>
+> For macOS users, installation of the GNU toolchain has been scripted and automated as part of 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.
 
 ### Configuration
 

scripts/config/vale/styles/Vocab/words/accept.txt

@@ -13,5 +13,6 @@ Trufflehog
 bot
 idempotence
 onboarding
+sed
 toolchain
 [A-Z]+s