Created scene, prefabs and scripts for startup UI

...ns/SimpleFileBrowser/Sprites/FileIcons/ExecutableIcon.png

...mpleFileBrowser/Sprites/FileIcons/ExecutableIcon.png.meta

...lugins/SimpleFileBrowser/Sprites/FileIcons/FolderIcon.png

...s/SimpleFileBrowser/Sprites/FileIcons/FolderIcon.png.meta

...ins/SimpleFileBrowser/Sprites/FileIcons/ImageFileIcon.png

...impleFileBrowser/Sprites/FileIcons/ImageFileIcon.png.meta

...s/Plugins/SimpleFileBrowser/Sprites/FileIcons/LICENSE.txt

...gins/SimpleFileBrowser/Sprites/FileIcons/LICENSE.txt.meta

...ugins/SimpleFileBrowser/Sprites/FileIcons/PdfFileIcon.png

.../SimpleFileBrowser/Sprites/FileIcons/PdfFileIcon.png.meta

...gins/SimpleFileBrowser/Sprites/FileIcons/TextFileIcon.png

...SimpleFileBrowser/Sprites/FileIcons/TextFileIcon.png.meta

...ins/SimpleFileBrowser/Sprites/FileIcons/VideoFileIcon.png

...impleFileBrowser/Sprites/FileIcons/VideoFileIcon.png.meta

...s/Plugins/SimpleFileBrowser/Sprites/ForwardArrow.psd.meta

...impleFileBrowser/Sprites/MultiSelectionToggleOff.psd.meta

...SimpleFileBrowser/Sprites/MultiSelectionToggleOn.psd.meta

...s/Plugins/SimpleFileBrowser/Sprites/ResizeCursor.psd.meta

.../SimpleFileBrowser/Sprites/SimpleFileBrowserDrag.psd.meta

...FileBrowser/Sprites/SimpleFileBrowserMoreOptions.psd.meta