Update README.md

fix typo again

Author: brookenf

README.md

@@ -4,7 +4,7 @@ This repository is for the Integrating With HubSpot I: Foundations course. This
 
 To read the full directions, please go to the [practicum instructions](https://app.hubspot.com/academy/l/tracks/1092124/1093824/5493?language=en).
 
-**Put your HubSpot developer test account custom objects URL link here:** https://app.hubspot.com/contacts/l/objects/{custom-obj-number}/views/all/list
+**Put your HubSpot developer test account custom objects URL link here:** https://app.hubspot.com/contacts/l/objects/${custom-obj-number}/views/all/list
 
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