Update development docs to use npm ci

Use npm ci instead of npm install for reproducible dependency installs
when building Node-RED from source.

Related to node-red/node-red#5424

Author: dimitrieh

docs/getting-started/development.md

@@ -50,7 +50,7 @@ Once you are on you your chosen branch, you should install all of the dependenci
 with the command:
 
 ```
-npm install
+npm ci
 ```
 
 ### Building Node-RED