Remove "fork on github banner"

[why]
Some code has been commented out. This can be removed. We can use git if
we want to access the code again in the future.

Furthermore the banner still is on the page, below the Sanky diagram (in
the small screen rendering position).

Signed-off-by: Fini Jastrow <ulf.fini.jastrow@desy.de>

_includes/css/nerd-font-tweaks.scss

@@ -475,67 +475,6 @@ a.nerd-font-button:before {
 	margin-left: -135px;
 }
 
-/* ----- fork on github banner ----- */
-/*
-#forkongithub a {
-	color: #fff;
-	background: #1E5D8A;
-	text-decoration: none;
-	font-family: arial, sans-serif;
-	text-align: center;
-	font-weight: 700;
-	font-size: 1rem;
-	line-height: 2rem;
-	position: relative;
-	transition: .5s;
-	padding: 5px 40px;
-}
-
-#forkongithub a::before,
-#forkongithub a::after {
-	content: "";
-	width: 100%;
-	display: block;
-	position: absolute;
-	top: 1px;
-	left: 0;
-	height: 1px;
-	background: #fff;
-}
-
-#forkongithub a::after {
-	bottom: 1px;
-	top: auto;
-}
-
-@media screen and (min-width:800px) {
-	#forkongithub {
-		position: fixed;
-		display: block;
-		top: 0;
-		right: 0;
-		width: 200px;
-		overflow: hidden;
-		height: 209px;
-		z-index: 99;
-	}
-
-	#forkongithub a {
-		width: 200px;
-		position: absolute;
-		top: 60px;
-		right: -60px;
-		transform: rotate(45deg);
-		-webkit-transform: rotate(45deg);
-		-ms-transform: rotate(45deg);
-		-moz-transform: rotate(45deg);
-		-o-transform: rotate(45deg);
-		box-shadow: 4px 4px 10px rgba(0, 0, 0, 0.8);
-		box-sizing: content-box;
-	}
-}
-*/
-
 // Github url button
 #github {
 	text-decoration: none;

_posts/2017-01-01-home.md

@@ -42,11 +42,6 @@ style: center container
 </a>
 <div class="text-left"><small><sub><em>Diagram created using <a href="http://sankeymatic.com/" title="SankeyMATIC (BETA): A Sankey diagram builder for everyone">SankeyMATIC</a></em></sub></small></div>
 </div>
-<span id="forkongithub">
-  <a href="{{ site.source_link }}">
-    <i class="nf nf-fa-code_fork"></i> Fork us on GitHub <i class="nf nf-fa-heart ow"></i>
-  </a>
-</span>
 
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