fix(guides): add missing link in installation

Author: skipjack

content/guides/installation.md

@@ -28,7 +28,7 @@ npm install --save-dev webpack
 npm install --save-dev webpack@<version>
 ```
 
-Installing locally is what we recommend for most projects. This makes it easier to upgrade projects individually when breaking changes are introduced. Typically webpack is run via one or more [NPM scripts]() which will look for a webpack installation in your local `node_modules` directory:
+Installing locally is what we recommend for most projects. This makes it easier to upgrade projects individually when breaking changes are introduced. Typically webpack is run via one or more [npm scripts](https://docs.npmjs.com/misc/scripts) which will look for a webpack installation in your local `node_modules` directory:
 
 ```json
 "scripts": {