Add Samsung logo (SVG) (#454)

* Added samsung_s.svg, samsung_swoop.svg and samsung.svg.

* Added Samsung icon to README.md.
Added reference image to images/reference/samsung.svg and updated images/reference/index.md correspondingly.

* Reduced the size of samsung_swoop.svg by 73 bytes.

* Added samsung_s.svg to README.txt and reference/index.md.
Removed samsung_swoop.svg.

images/reference/index.md

@@ -246,4 +246,6 @@ Where possible this links to the organisation's brand guidelines page.
 | <img src="/images/svg/fritz.svg" width="256" /> | <img src="/images/reference/Fritz!.svg" width="256" /> | https://en.wikipedia.org/wiki/Fritz!Box#/media/File:Fritz!.svg |
 | <img src="/images/svg/friendica.svg" width="256" /> | <img src="/images/reference/friendica.png" width="256" /> | https://github.com/friendica/friendica/tree/develop/images |
 | <img src="/images/svg/wireguard.svg" width="256" /> | <img src="/images/reference/wireguard.svg" width="256" /> | https://www.wireguard.com/img/emblem-circle.svg |
-| <img src="/images/svg/freecodecamp.svg" width="256" /> | <img src="/images/reference/freecodecamp.svg" width="256" /> | https://design-style-guide.freecodecamp.org |
+| <img src="/images/svg/freecodecamp.svg" width="256" /> | <img src="/images/reference/freecodecamp.svg" width="256" /> | https://design-style-guide.freecodecamp.org |
+| <img src="/images/svg/samsung.svg" width="256" /> | <img src="/images/reference/samsung.svg" width="256" /> | https://commons.wikimedia.org/wiki/File:Samsung_Logo.svg |
+| <img src="/images/svg/samsung_s.svg" width="256" /> | <img src="/images/reference/samsung.svg" width="256" /> | https://commons.wikimedia.org/wiki/File:Samsung_Logo.svg |