favicon and og:image energy

[ryanve]

uses images from #5 #6 #7

<!-- https://github.com/s9a/E/issues?q=img -->
<meta property="og:image" content="https://user-images.githubusercontent.com/949985/49286340-b8366880-f44e-11e8-8d16-5625f5abdb1e.png">
<meta property="og:image:alt" content="helix">
<meta property="og:image" content="https://user-images.githubusercontent.com/949985/49285520-760c2780-f44c-11e8-9c42-e77618f14e99.png">
<meta property="og:image:alt" content="E">
<meta property="og:image" content="https://user-images.githubusercontent.com/949985/49283650-224b0f80-f447-11e8-8592-96e12c2c2113.JPG">
<meta property="og:image:alt" content="E=she">

<!-- https://github.com/s9a/E/issues?q=favicon -->
<link rel="shortcut icon" href="https://user-images.githubusercontent.com/949985/49285520-760c2780-f44c-11e8-9c42-e77618f14e99.png">