add back link to audience file and update package.json

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@lob/openapi",
-  "version": "1.19.28",
+  "version": "1.19.29",
   "engines": {
     "node": ">=14.16.0",
     "npm": ">=7.9.0"

shared/models/qr_code_campaigns.yml

@@ -31,7 +31,7 @@ properties:
     description: |
       Redirect all mail recipients to either a single URL or specify a unique URL for each recipient.
       To redirect all mail recipients in a campaign to the same URL, assign the desired URL to this field.
-      To redirect each mail recipient to a unique URL, leave this field empty and specify the redirect link for each row in the audience file. Then, when creating a new upload, map this column to the `qr_code_redirect_url` key in the `mergeVariableColumnMapping` property. 
+      To redirect each mail recipient to a unique URL, leave this field empty and specify the redirect link for each row in the [audience file](https://help.lob.com/print-and-mail/building-a-mail-strategy/campaign-or-triggered-sends/campaign-audience-guide). Then, when creating a new upload, map this column to the `qr_code_redirect_url` key in the `mergeVariableColumnMapping` property. 
 
       Note: Failing to set or map the redirect URL when using QR codes may lead to errors in generating mail pieces.
     oneOf: