Webpack: Emphasise need for --config if no webpack.config.js (e.g. webpack-merge)

[MaoShizhong]

Because

A recent problem a fellow learner was facing was the result of using webpack-merge (which is mentioned in step 4 of the webpack lesson. Whilst the assignment tutorial does show using the --config option to specify a command use a particular webpack config file, it does not explain what happens if you omit it and that no specified file will cause webpack to search for some default files (including webpack.config.js, which is what the previous tutorials show using).

The above learner's watch command was likely taken from a previous tutorial showing it, where it simply showed webpack --watch since the tutorial was using a webpack.config.js file and thus did not need the --config option. Since they did not include this and they were using files named as per the merge tutorial, they encountered an error.

This PR adds a little step 4.1 just emphasising that if someone did use webpack-merge and/or didn't have a webpack-config.js file, then they'd need to use the --config option to specify which config file a command should run. This should hopefully reduce the chance of such an error reoccurring, as the webpack docs do not clearly highlight this from the linked tutorials.

This PR

• Add step 4.1 emphasising --config if no file named webpack.config.js

Issue

N/A

Additional Information

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[01zulfi]

lgtm 🚀