Update HTTP REST API

HTTP-REST-API.md

@@ -4,7 +4,7 @@
 
 The Repertory HTTP REST API uses hashed passwords for authentication.
 
-Before making requests to any protected endpoint, hash your password using **BLAKE2b-384** 
+Before making requests to any protected endpoint, hash your password using **BLAKE2b-384**, convert it to a hex string, 
 and provide it according to the API's authentication requirements.
 
 Example in C++: