hugo: use new hugo-book edit link feature

Remove custom footer template and only override the edit link partial
with the custom book index replace logic. This helps to reduce future
incompatibility by minimizing overwritten templates.

Author: anthraxx

website/config.toml

@@ -29,7 +29,7 @@ theme = "hugo-book"
   BookPortableLinks = true
   BookRepo = 'https://github.com/uapi-group/kernel-features'
   BookCommitPath = 'commit'
-  BookEditPath = 'edit/main'
+  BookEditLink = '{{ .Site.Params.BookRepo }}/edit/main/{{ .Path }}'
   BookIndexPage = 'README.md'
 
 [modules]

website/layouts/partials/docs/footer.html

@@ -0,0 +1,5 @@
+{{- return (partial "docs/text/template" (dict "Template" .Site.Params.BookEditLink "Context" (dict
+"Site" .Site
+"Page" .Page
+"Path" (strings.TrimPrefix hugo.WorkingDir ( replace .Page.File.Path "_index.md" .Site.Params.BookIndexPage))
+)) | urls.JoinPath) -}}