Update signing.md

Author: prince-chrismc

docs/signing.md

@@ -2,7 +2,7 @@
 
 ## Custom Signature Algorithms
 
-The libraries design is open so you can implement your own algorithms, see [existing examples](https://github.com/Thalhammer/jwt-cpp/blob/73f23419235661e89a304ba5ab09d6714fb8dd94/include/jwt-cpp/jwt.h#L874) for ideas.
+The libraries design is open so you can implement your own algorithms, see [existing implementations](https://github.com/Thalhammer/jwt-cpp/blob/73f23419235661e89a304ba5ab09d6714fb8dd94/include/jwt-cpp/jwt.h#L874) for ideas.
 
 ```cpp
 struct your_algorithm{