Update README.md

Author: XenoBytesX

bootcamp/materials/1-dimensional-data-modeling/README.md

@@ -47,7 +47,7 @@ There are two methods to get Postgres running locally.
 2. Run this command after replacing **`<computer-username>`** with your computer's username:
 
     ```bash
-    pg_restore -c --if-exists -U user -d postgres data.dump
+    pg_restore -c --if-exists -U <computer-username> -d postgres data.dump
     ```
 
     If you have any issue, the syntax is `pg_restore -U [username] -d [database_name] -h [host] -p [port] [backup_file]`