Various changes to allow for contributors to run and package app by themselves

[alchzh]

• Removed references to C:/Users/awnad/... in package.json
• Fixed font handling (materialize-css doesn't come with the fonts we need and the references didn't use the gulp copied directory)
• Added package-lock.json (see https://docs.npmjs.com/files/package-lock.json )

[alchzh]

The way this is set up the process should be

1. clone
2. npm ci
3. npx gulp css js fonts
4. npm run pack-all
5. Everything is now in dist\pkg\...