Add ghcode shortcode for rendering github content

Author: nginx-jack

README.md

@@ -52,6 +52,20 @@ This theme contains the following custom shorcodes:
 
 - openapi.html - Render an OpenAPI spec using ReDoc.
 - metrics.html - Imports data from a JSON file and presents it in table format.
+- ghcode.html - Rendering code from github
+
+#### `ghcode` example
+To render code directly from github at build time, you can use the `ghcode` shortcode.
+
+_Param 1_ - The url for the `raw` github file you want to render
+
+_Param 2_ - Options for highlighting following Hugo's [Highlight shortcode](https://gohugo.io/content-management/syntax-highlighting/#highlight-shortcode)
+
+```
+{{< ghcode "https://raw.githubusercontent.com/nginxinc/kubernetes-ingress/refs/heads/main/examples/custom-resources/access-control/access-control-policy-allow.yaml" "hl_lines=4" >}}
+```
+
+
 
 ### Includes
 

layouts/shortcodes/ghcode.html

@@ -0,0 +1,12 @@
+{{ $file := .Get 0 }}
+{{ $params := .Get 1 }}
+{{ with resources.GetRemote $file }}
+  {{ with .Err }}
+    {{ errorf "%s" . }}
+  {{ else }}
+    {{ $lang := path.Ext $file | strings.TrimPrefix "." }}
+    {{ highlight .Content $lang $params }}
+  {{ end }}
+{{ else }}
+  {{ errorf "Unable to load github content from %s from %q" $file .Position}}
+{{ end }}