[docs] Fix site_url - take 2

docs/_includes/set-global-site-url.html

@@ -0,0 +1,12 @@
+{% comment %}
+This is a hack to force using HTTPS...
+The URL of the docs should be changed in the repo settings instead
+{% endcomment %}
+{% assign protocol_scheme = page.url | absolute_url | truncate: 5, "" %}
+{%- capture site_url -%}
+  {%- if protocol_scheme == "https" -%}
+    {{ site.github.url | replace: "http://", "https://" }}
+  {%- else -%}
+    {{ site.github.url }}
+  {%- endif -%}
+{%- endcapture -%}