Add GSoC link in header

_static/images/gsoc.svg

+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg
+   id="svg51"
+   version="1.1"
+   viewBox="0 0 175.60001 175.60001"
+   height="175.60001"
+   width="175.60001"
+   sodipodi:docname="gsoc.svg"
+   inkscape:version="1.3 (0e150ed6c4, 2023-07-21)"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:dc="http://purl.org/dc/elements/1.1/">
+  <sodipodi:namedview
+     id="namedview1"
+     pagecolor="#ffffff"
+     bordercolor="#000000"
+     borderopacity="0.25"
+     inkscape:showpageshadow="2"
+     inkscape:pageopacity="0.0"
+     inkscape:pagecheckerboard="0"
+     inkscape:deskcolor="#d1d1d1"
+     inkscape:zoom="0.89583635"
+     inkscape:cx="55.813766"
+     inkscape:cy="102.69733"
+     inkscape:window-width="1920"
+     inkscape:window-height="1052"
+     inkscape:window-x="0"
+     inkscape:window-y="0"
+     inkscape:window-maximized="1"
+     inkscape:current-layer="svg51" />
+  <metadata
+     id="metadata55">
+    <rdf:RDF>
+      <cc:Work
+         rdf:about="">
+        <dc:format>image/svg+xml</dc:format>
+        <dc:type
+           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
+        <dc:title>logo_lockup_summer_of_code_horizontal_Roboto</dc:title>
+      </cc:Work>
+    </rdf:RDF>
+  </metadata>
+  <!-- Generator: Sketch 3.7.2 (28276) - http://www.bohemiancoding.com/sketch -->
+  <title
+     id="title2">logo_lockup_summer_of_code_horizontal_Roboto</title>
+  <desc
+     id="desc4">Created with Sketch.</desc>
+  <defs
+     id="defs6" />
+  <g
+     id="Group"
+     transform="translate(-52.6,-0.9)">
+    <path
+       style="fill:#fbbc05"
+       d="m 114.7,150.8 25.7,25.7 25.7,-25.7 h 36.4 V 114.4 L 228.2,88.7 202.5,63 V 26.6 H 166.1 L 140.4,0.9 114.7,26.6 H 78.3 V 63 l -25.7,25.7 25.7,25.7 v 36.4 z"
+       id="Shape" />
+    <path
+       style="fill:#ffffff"
+       id="path11"
+       d="m 143.2,61.2 -0.1,0.4 -11.9,52.5 -0.4,2 h 7.4 l 0.1,-0.4 11.9,-52.5 0.4,-2 z m -18.9,7.2 -1,0.7 -21.5,16.7 -1.4,1.1 v 3.4 l 1.4,1.1 21.5,16.7 1,0.7 v -9 L 109.8,88.7 124.3,77.4 Z m 32.2,0 v 9 L 171,88.7 156.5,100 v 9 l 1,-0.7 21.5,-16.7 1.4,-1.1 V 87.1 L 179,86 157.4,69.2 Z" />
+    <circle
+       id="Oval"
+       cx="140.39999"
+       cy="88.699997"
+       r="58.700001"
+       style="fill:none;stroke:#ffffff;stroke-width:8" />
+  </g>
+</svg>

conf.py

@@ -87,6 +87,13 @@ html_theme_options = {
             "type": "local",
             "attributes": {"target": "_blank"},
         },
+        {
+            "name": "GSoC",
+            "url": "https://summerofcode.withgoogle.com/",
+            "icon": "_static/images/gsoc.svg",
+            "type": "local",
+            "attributes": {"target": "_blank"},
+        },
     ],
     "use_edit_page_button": True,
     "show_toc_level": 1,