add demo gif
add demo gif


Former-commit-id: 5c8a9af0d516b549700ca0695e0878e55d3b6ab3
instructure/react-avatar-editor,hu9o/react-avatar-editor,codemanki/react-avatar-editor,rtorr/react-avatar-editor,peterssonjesper/react-avatar-editor,hu9o/react-avatar-editor,ainsleys/react-avatar-editor,joinoneroom/react-avatar-editor,instructure/react-avatar-editor,cptroot/react-avatar-editor,mosch/react-avatar-editor,ainsleys/react-avatar-editor,mosch/react-avatar-editor,mosch/react-avatar-editor,KonishiLee/react-avatar-editor,cptroot/react-avatar-editor,nmn/react-avatar-editor,codemanki/react-avatar-editor,joinoneroom/react-avatar-editor,KonishiLee/react-avatar-editor,nmn/react-avatar-editor,peterssonjesper/react-avatar-editor,rtorr/react-avatar-editor