Steps to build dropzone for RT

1) Download a release from github(https://github.com/NicolasCARPi/dropzone/releases) and unpack:

    tar zxvf 7.2.0.tar.gz

2) Build with yarn, installing additional packages as needed:

    brew install node
    corepack enable
    yarn install
    yarn build

3) The above should create a dist directory. Copy files from there to RT.

    cp /path/to/src/dropzone-7.2.0/dist/dropzone.js devel/third-party/dropzone-7/
    cp /path/to/src/dropzone-7.2.0/dist/dropzone-min.js share/static/js/dropzone.min.js
    cp /path/to/src/dropzone-7.2.0/dist/dropzone.css share/static/css/elevator/

4) Edit dropzone.css and dropzone.min.js and remove the sourceMappingURL comment at the end.
