Add search for C++ string algorithms on GitHub to section Notes and references [ci skip]

Author: martinmoene

README.md

@@ -210,10 +210,9 @@ Define this to 1 if you want to compile without exceptions. If not defined, the
 
 ## Notes and references
 
-TBD
-
 - [n3593 - std::split(): An algorithm for splitting strings](http://wg21.link/n3593). / https://isocpp.org/files/papers/n3593.html
 - [Martin Broadhurst. Exploring String Splitting in C++ Programming. 2023](http://www.martinbroadhurst.com/how-to-split-a-string-in-c.html).
+- [Search GitHub for C++ string algorithms](https://github.com/topics/string-algorithms?l=c%2B%2B).
 
 ## Appendix