docs: Developer instructions for native Node addons (#13121)

* docs: Developer instructions for native Node addons

Credits for actually finding this easy method goes to @nornagon.

* :memo: Of course there's a typo

docs/tutorial/using-native-node-modules.md

@@ -67,6 +67,16 @@ The `HOME=~/.electron-gyp` changes where to find development headers. The
 where to download the headers. The `--arch=x64` says the module is built for
 64bit system.
 
+### Manually building for a custom build of Electron
+
+To compile native Node addons against a custom build of Electron that doesn't
+match a public release, instruct `npm` to use the version of Node you have bundled
+with your custom build.
+
+```sh
+npm rebuild --nodedir=$HOME/.../path/to/electron/vendor/node
+```
+
 ## Troubleshooting
 
 If you installed a native module and found it was not working, you need to check