Add OGP title and description

[tossy310]

We currently only have og image.

livesite/frontend/public/index.html

Line 7 in d9a548b

<meta property="og:image" content="https://storage.googleapis.com/icpcsec/images/icpc-logo_8x.png">

[tossy310]

idea - use https://github.com/jantimon/html-webpack-plugin

[tossy310]

and also favicon