[breaking] Make file-loader a peerDependency

[rpaasche]

Define devDependency as devDependencies.

Otherwise users of this package hast to use the same webpack version. Currently ther are some copatibility issues with create-rect-app projects and the file-loader version in this project.

[wojtekmaj]

See #911 (comment)

[wojtekmaj]

This one is a normal dependency though. It gets imported in virtually all components. If it's missing, the project won't build.

[rpaasche]

Right but it's a compiletime dependency (devDependency) the final build includes no information about prop-types.

[wojtekmaj]

That depends. The code built on my side does include propTypes, so if you use it in your project, prop-types package will be required.

It's up to developer's bundler configuration wherever propTypes are being removed or not.

Even if we decide to strip it off on our side, which doesn't make a lot of sense to me, then we would need to ship development and production versions of the code, and still, development version would require prop-types.

So, dependency must stay.

[rpaasche]

changed it back.

[rpaasche]

Marked file-loader as peer now.

[wojtekmaj]

This looks good to me. We will have to wait for the next breaking version though, as this requires user to install file-loader manually to use Webpack-specific entry.

[pleerock]

yeap so there is a major problem for the users using react-pdf with other bundlers like vite and others:

└─┬ react-pdf
  └─┬ file-loader
    └── ✕ missing peer webpack@"^4.0.0 || ^5.0.0"

It requires webpack installation, but I do not use or need webpack. I don't feel this PR will resolve this issue, because I'll have to install file-loader (thus webpack) anyway.

[rpaasche]

The second commit of this PR marks the peer as optional, so neither NPM nor yarn will install it without you to add it to your own package.json.