site-root: update Tangled logo (#2090)

## Changes

Update the [Tangled](https://tangled.org) logo to the new, proper one:
Dolly!
Also swap tangled.sh to the new
[tangled.org](https://bsky.app/profile/tangled.org/post/3lz5dmdtl4s2s)
domain.

Author: dscho

layouts/partials/site-root.html

@@ -67,7 +67,7 @@ <h3 class="text-center">Products providing Git hosting</h3>
     (dict "name" "codeberg" "url" "https://codeberg.org")
     (dict "name" "sourcehut" "url" "https://sourcehut.org")
     (dict "name" "gitea" "url" "https://gitea.com")
-    (dict "name" "tangled" "url" "https://tangled.sh")
+    (dict "name" "tangled" "url" "https://tangled.org")
     (dict "name" "radicle" "url" "https://radicle.xyz")
     (dict "name" "gerrit" "url" "https://www.gerritcodereview.com")
     (dict "name" "azure-repos" "url" "https://azure.microsoft.com/en-us/products/devops/repos/")