docs: fix 404 styling (#18094) (#18106)

* docs: fix 404 styling



* hack around custom tag destruction



---------

Signed-off-by: Michael Crenshaw <350466+crenshaw-dev@users.noreply.github.com>
Co-authored-by: Michael Crenshaw <350466+crenshaw-dev@users.noreply.github.com>

hack/gen-docs/main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"bytes"
 	"fmt"
 	"log"
 	"os"
@@ -61,6 +62,11 @@ func updateMkDocsNav(parent string, child string, subchild string, files []strin
 	if err != nil {
 		return err
 	}
+
+	// The marshaller drops custom tags, so re-add this one. Turns out this is much less invasive than trying to handle
+	// it at the YAML parser level.
+	newmkdocs = bytes.Replace(newmkdocs, []byte("site_url: READTHEDOCS_CANONICAL_URL"), []byte("site_url: !ENV READTHEDOCS_CANONICAL_URL"), 1)
+
 	return os.WriteFile("mkdocs.yml", newmkdocs, 0644)
 }
 

mkdocs.yml

@@ -213,6 +213,7 @@ nav:
 - Blog ⧉: https://blog.argoproj.io/
 repo_url: https://github.com/argoproj/argo-cd
 site_name: Argo CD - Declarative GitOps CD for Kubernetes
+site_url: !ENV READTHEDOCS_CANONICAL_URL
 strict: true
 theme:
   custom_dir: overrides