Update catalog.md

fixed typo.

Author: Haley Van Dyck

catalog.md

@@ -53,7 +53,7 @@ Agencies must follow the provided [specification](/schema/).  We have built a [c
 Inclusion of the Public Data Listing as a Record
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-Each 'data.json' catalog file should include a record for the data asset that is the data catalog itself.  Contact Name and Contact Email can be used to provide a PoC for the 'data.json' efforts;  Description can be used to clarify which version of the common core metadata schema the agency is currently using; and Last Update can be used to indicate the date when the Public Data Listing was last mmodified.  
+Each 'data.json' catalog file should include a record for the data asset that is the data catalog itself.  Contact Name and Contact Email can be used to provide a PoC for the 'data.json' efforts;  Description can be used to clarify which version of the common core metadata schema the agency is currently using; and Last Update can be used to indicate the date when the Public Data Listing was last modified.  
 
 Presentation
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