Add instructions for compiling VSCode yourself; explanation

replace/vscode.md

@@ -8,6 +8,12 @@ layout: replace
 
 While Visual Studio Code's source code is FOSS, the official builds are [proprietary software.](https://github.com/Microsoft/vscode/issues/60#issuecomment-161792005) There are FOSS alternatives that create FOSS builds of Visual Studio Code.
 
+This is evidenced by [a comment made by a Microsoft developer](https://web.archive.org/web/20200621195204/https://github.com/Microsoft/vscode/issues/60#issuecomment-161792005):
+
+> When we [Microsoft] build Visual Studio Code, we do exactly this. We clone the vscode repository, we lay down a customized product.json that has Microsoft specific functionality (telemetry, gallery, logo, etc.), and then produce a build that we release under our license.
+>
+> When you clone and build from the vscode repo, none of these endpoints are configured in the default product.json. Therefore, you generate a “clean” build, without the Microsoft customizations, which is by default licensed under the MIT license.
+
 ---
 
 ## VSCodium
@@ -19,3 +25,11 @@ Binary releases of VS Code without MS branding / telemetry / licensing.
   - **Source code**: [GitHub](https://github.com/VSCodium/vscodium)
   - **License**: [MIT](https://github.com/VSCodium/vscodium/blob/master/LICENSE)
 {% endinfobox %}
+
+## Compiling VSCode yourself
+
+Microsoft have a guide for compiling your own copy of Visual Studio code.
+
+{% infobox %}
+  - **Guide**: [GitHub](https://github.com/Microsoft/vscode/wiki/How-to-Contribute#build-and-run)
+{% endinfobox %}