doc(prompts): Add redirect to fix broken link on Prompts Page (#8408)

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Co-authored-by: Bagatur <baskaryan@gmail.com>

docs/docs_skeleton/vercel.json

@@ -3448,6 +3448,10 @@
       "source": "/docs/modules/model_io/models/llms/integrations/writer",
       "destination": "/docs/integrations/llms/writer"
     },
+    {
+      "source": "/en/latest/modules/prompts.html",
+      "destination": "/docs/modules/model_io/prompts"
+    },
     {
       "source": "/en/latest/modules/prompts/output_parsers.html",
       "destination": "/docs/modules/model_io/output_parsers/"