added webpack-encore for managing frontend assets #113 (#122)

* updated installation docu #113
* rewritten login page #113
* added icheck plugin #113
* changed to YesNoType in edit forms #113
* updated CONTRIBUTING.md #113
* added start of developer docu #113
* added compile scripts and compiled assets #113

webpack.config.js

@@ -0,0 +1,40 @@
+var Encore = require('@symfony/webpack-encore');
+
+Encore
+    // the project directory where compiled assets will be stored
+    .setOutputPath('public/build/')
+
+    // the public path used by the web server to access the previous directory
+    .setPublicPath('/build/')
+
+    // delete old files before creating them
+    .cleanupOutputBeforeBuild()
+
+    // add debug data in development
+    .enableSourceMaps(!Encore.isProduction())
+
+    // uncomment to create hashed filenames (e.g. app.abc123.css)
+    .enableVersioning(Encore.isProduction())
+
+    // generate only two files: app.js and app.css
+    .addEntry('app', './assets/js/app.js')
+
+    // enable sass/scss parser
+    .enableSassLoader()
+
+    // show OS notifications when builds finish/fail
+    .enableBuildNotifications()
+
+    // empty the outputPath dir before each build
+    .cleanupOutputBeforeBuild()
+
+    // load jquery as Kimai and AdminLTE rely on it
+    .autoProvidejQuery()
+
+    // see https://symfony.com/doc/current/frontend/encore/bootstrap.html
+    .enableSassLoader(function(sassOptions) {}, {
+        resolveUrlLoader: false
+    })
+;
+
+module.exports = Encore.getWebpackConfig();