Adapt docs to webpack 2

[obestwalter]

Webpack 2 is out and there are a lot of breaking changes.

The README needs to be adapted to webpack 2 but I did not completely sort out what needs to be adjusted. Also there are a lot of recommendations in the webpack issues to go back to some 2.x.beta version so it might be a good idea to wait a while to jump on 2.x.

@StefanYohansson addressed some important issues already in #13 (comment) but the ExtractTextPlugin config needs to be adjusted as well.

This seems to be a helpful article about the migration: http://javascriptplayground.com/blog/2016/10/moving-to-webpack-2/

I don't know my way aroud too well around this fancy webdev stuff yet to provide the finished solution, so I would propose until somebody else does to add some version pinning to the README
I made it work for me with this install invocation:

npm install --save-dev \
    [email protected] \
    [email protected] \
    babel-loader \
    css-loader \
    file-loader \
    node-sass \
    sass-loader \
    style-loader \
    url-loader \
    webpack babel-core \

[torian257x]

this still results in an error to me. I get when installing via npm install --save-dev [email protected] [email protected] babel-loader css-loader file-loader de-sass sass-loader style-loader url-loader webpack babel-core

├─┬ [email protected] 
│ └── [email protected] 
└─┬ UNMET PEER DEPENDENCY [email protected]
  ├── [email protected] 
  ├─┬ [email protected] 
  │ └── [email protected] 
  ├─┬ UNMET PEER DEPENDENCY [email protected]

then when starting I get the same annoying error again

jossnaz@osboxes:~/IdeaProjects/lektor_ironscales/src/webpack$ cd ..
jossnaz@osboxes:~/IdeaProjects/lektor_ironscales/src$ lektor server -f webpack
 * Project path: /home/jossnaz/IdeaProjects/lektor_ironscales/src/lektor_ironscales.lektorproject
 * Output path: /home/jossnaz/.cache/lektor/builds/aee0e3bca93424dd2c4f468dc6ad4bdb
Started source info update
Finished source info update in 0.13 sec
Started build
Running npm install
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@^1.0.0 (node_modules/chokidar/node_modules/fsevents):
npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for [email protected]: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"x64"})
npm WARN [email protected] requires a peer of ajv@>=5.0.0 but none was installed.
npm WARN [email protected] requires a peer of webpack@^1.9.11 but none was installed.
 * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@^1.0.0 (node_modules/chokidar/node_modules/fsevents):
npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for [email protected]: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"x64"})
npm WARN [email protected] requires a peer of ajv@>=5.0.0 but none was installed.
npm WARN [email protected] requires a peer of webpack@^1.9.11 but none was installed.
Starting webpack build
Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
 - configuration.resolve has an unknown property 'modulesDirectories'. These properties are valid:
   object { alias?, aliasFields?, cachePredicate?, cacheWithContext?, descriptionFiles?, enforceExtension?, enforceModuleExtension?, extensions?, fileSystem?, mainFields?, mainFiles?, moduleExtensions?, modules?, plugins?, resolver?, symlinks?, unsafeCache?, useSyncFileSystemCalls? }
 - configuration.resolve.extensions[0] should not be empty.
Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
 - configuration.resolve has an unknown property 'modulesDirectories'. These properties are valid:
   object { alias?, aliasFields?, cachePredicate?, cacheWithContext?, descriptionFiles?, enforceExtension?, enforceModuleExtension?, extensions?, fileSystem?, mainFields?, mainFiles?, moduleExtensions?, modules?, plugins?, resolver?, symlinks?, unsafeCache?, useSyncFileSystemCalls? }
 - configuration.resolve.extensions[0] should not be empty.
Webpack build finished
Finished build in 3.67 sec
Started prune

my package.json

{
  "name": "lektor-webpack",
  "version": "1.0.0",
  "private": true,
  "devDependencies": {
    "babel-core": "^6.25.0",
    "babel-loader": "^7.1.1",
    "css-loader": "^0.28.4",
    "extract-text-webpack-plugin": "^1.0.1",
    "file-loader": "^0.11.2",
    "node-sass": "^4.5.3",
    "sass-loader": "^6.0.6",
    "style-loader": "^0.18.2",
    "url-loader": "^0.5.9",
    "webpack": "^3.2.0"
  }
}

[obestwalter]

I guess this has been resolved in some other way? I am not using this project anymore so I don't know, but if it would still be a problem there would be some activity here.