add Sourcegraph (#1156)

* add Sourcegraph

* Update simple-icons.json

Change Sourcegraph source to base repository, the logo's can be found (currently) in `website/static/sourcegraph`

_data/simple-icons.json

@@ -2050,6 +2050,11 @@
             "hex": "535353",
             "source": "https://sourceforge.net/"
         },
+        {
+            "title": "Sourcegraph",
+            "hex": "00B4F2",
+            "source": "https://github.com/sourcegraph/about"
+        },
         {
             "title": "SparkFun",
             "hex": "E53525",

icons/sourcegraph.svg

@@ -0,0 +1 @@
+<svg role="img" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><title>Sourcegraph icon</title><path d="M9.341.002a2.56 2.56 0 0 0-.484.069C7.501.379 6.7 1.735 7.007 3.092L8.412 8.14 3.368 6.485C2.073 6.053.655 6.793.223 8.088c-.431 1.295.31 2.714 1.603 3.146l5.853 1.919-4.063 4.556a2.635 2.635 0 0 0-.618 1.666 2.474 2.474 0 0 0 2.467 2.466c.678 0 1.357-.308 1.85-.863l3.563-3.979 1.433 5.151A2.498 2.498 0 0 0 14.716 24h.001c.185 0 .431-.061.617-.123a2.514 2.514 0 0 0 1.726-3.084l-1.38-5.017 4.957 1.625c.309.062.556.123.802.123 1.111 0 2.036-.678 2.343-1.726.433-1.296-.308-2.714-1.603-3.146l-5.728-1.878 4.063-4.537c.925-1.048.863-2.59-.185-3.514-1.049-.926-2.59-.864-3.516.184l-3.571 4.006-1.424-5.178C11.494.655 10.462-.046 9.34.002z"/></svg>