fix readme.

fix readme

README.md

@@ -17,7 +17,7 @@ CrestApi project structure:
 ## Installation
 We provide this code as a standalone library.
 It requires:
-* the `nlhomann` JSON library
+* the `nlhomann` JSON library (this is delivered within this package)
 * the `CURL` library
 * the `BOOST` library