fix(comment): moved waline placeholder parameter to locale.placeholder (CaiJimmy#914)

fix waline parameter

Author: L-Super

config.yaml

@@ -70,7 +70,7 @@ params:
             clientSecret:
             autoCreateIssue: false
 
-        # Waline client configuration see: https://waline.js.org/en/reference/client.html
+        # Waline client configuration see: https://waline.js.org/en/reference/client/props.html
         waline:
             serverURL:
             lang:
@@ -81,9 +81,9 @@ params:
             requiredMeta:
                 - nick
                 - mail
-            placeholder:
             locale:
                 admin: Admin
+                placeholder:
 
         twikoo:
             envId: