The Gulp.js build assets are currently generated and placed inside the src/wikipedia.org/ folder along with the uncompiled source files. This makes it difficult to distinguish which assets are produced by the Gulp build and which are manually edited.

To more cleanly see this distinction, we should place all the build assets into a separate, top-level dev folder that mimics the folder structure of the src folder.

The following files should be moved into the new folder:

• Compiled handlebars files index.html
• Compiled PostCSS files assets/postcss/
• Compiled translation files assets/l10n/
• Compiled images (the sprite file) & logo images should be copied over

This move will involve several changes to the Gulp build process. First to output the files into a new directory, and second to compress and minify those files from the new directory into production.