Fixes the missing images in the Logo story.
The current method of downloading the images into
docs/ui/assets and treating them as static assets
(with the start-storybook -s option) could be problematic
if that directory is deleted or "cleaned" before the
storybook build.
Instead, the images are now downloaded into
./storybook/resolve-imports and imported explicitly in the
code in Logo.stories.data.js.
* ./storybook/resolve-less-imports renamed to resolve-imports
* .gitignore is updated to reflect that
* Webpack config is updated with the `resolve-imports` path
* static option (-s) is removed from npm start script
* Images are explicitly imported in Logo.stories.data.js
* Type definitions are added for .svg and .png files
Change-Id: I242d229242c86a5784d6d4611d0b9c7049712dac
6907c81a15