fix: correct recipe count to 425, scope site count to recipes section

README had 426 (off by one due to _index.md). Homepage and footer now
use where .Site.RegularPages "Section" "recipes" to exclude non-recipe
pages like /imprint/ from the count.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

layouts/index.html

@@ -1,5 +1,5 @@
 {{ define "main" }}
-  {{- $pages     := .Site.RegularPages -}}
+  {{- $pages     := where .Site.RegularPages "Section" "recipes" -}}
   {{- $featured  := first 8 (shuffle $pages) -}}
   {{- $hero      := index (shuffle $pages) 0 -}}
   {{- $cats      := .Site.Taxonomies.categories.ByCount -}}