doc: drop the --production flag for installing windows-build-tools

This isn't needed, and was probably copy-pasted from
windows-build-tools' README.md, which has since been changed
to drop the `--production` flag from the install instructions.

PR-URL: #2206
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Christian Clauss <cclauss@me.com>
Reviewed-By: Rod Vagg <rod@vagg.org>

README.md

@@ -49,7 +49,7 @@ Install the current version of Python from the [Microsoft Store package](https:/
 
 #### Option 1
 
-Install all the required tools and configurations using Microsoft's [windows-build-tools](https://github.com/felixrieseberg/windows-build-tools) using `npm install --global --production windows-build-tools` from an elevated PowerShell or CMD.exe (run as Administrator).
+Install all the required tools and configurations using Microsoft's [windows-build-tools](https://github.com/felixrieseberg/windows-build-tools) using `npm install --global windows-build-tools` from an elevated PowerShell or CMD.exe (run as Administrator).
 
 #### Option 2