feat: support Artalk comment system (#1306)

* feat: support artalk comment system

* chore: change url from testingcf to cdn prefix

* refactor(comments): align artalk provider style and keep custom css overrides

* fix: update Artalk CDN links to use the correct URL

* refactor(comments): simplify Artalk implementation

* fix(artalk): update script tag to use ESM for Artalk

* fix(artalk): set locale to 'auto' for Artalk comments

* refactor: move artalk style and script link to external.toml

---------

Co-authored-by: Jimmy Cai <jimmy@cai.im>

config/_default/params.toml

@@ -101,6 +101,10 @@ SortBy         = "default"
     enabled  = true
     provider = "disqus"
 
+    [comments.artalk]
+        serverUrl = ""
+        site      = ""
+
     [comments.disqusjs]
         shortname  = ""
         apiUrl     = ""