[WIP][FEAT]: Add API pages for Avatar, Dropone, FileCard, FileMosaic, FIleInputButton, FullScreen, ImagePreview and VideoPreview

26 add avatar demo page and finish avatar component

Merge pull request #13 from files-ui/26-feat-add-fileinputbutton-demo-page-and-finish-finleinputbutton-component

26 feat add fileinputbutton demo page and finish finleinputbutton component

[WIP][REF]: Add disableRipple and disabled demos. Bug in disabled, it disabled buttons in all page. Saving changes and creating a branch for this bug

[WIP][FEAT]: Add styling section for input button component: color, text color, variant, text transform

Merge pull request #12 from files-ui/25-feat-add-dropzone-component-missing-features-and-finish-dropzone-demo-page

25 feat add dropzone component missing features and finish dropzone demo page

[MVP]: Finished Dropzone component and dropzone demo page. Last features were behaviour code and demo components.

[FIX]: Refactor make styles for dropzone to return also the disabled layer classname to set a color according to the main color

[FIX]: Solve issue when multiple dropzones are in the same page. Specify a unique id for each dropzone drop layer and styles related to border and bg color

[FIX]: Sole issue when multiple dropzones are in the same page. Specify a unique id for each dropzone and styles related to border, color footer, header and ripple