Update unsupported-features.md

Author: pgbovine

unsupported-features.md

@@ -62,7 +62,7 @@ Due to this ultra-focused design, the following features are not supported and w
 - [struct members declared as unbounded arrays](https://github.com/pgbovine/opt-cpp-backend/issues/73)
 - [mixed pointer/array declared types](https://github.com/pgbovine/opt-cpp-backend/issues/74)
 - [static array initializers](https://github.com/pgbovine/opt-cpp-backend/issues/75)
-- C++ STL and string objects aren't visualized nicely (see [GitHub issue](https://github.com/pgbovine/OnlinePythonTutor/issues/256))
+- C++ STL containers and strings aren't visualized nicely (see [GitHub issue](https://github.com/pgbovine/OnlinePythonTutor/issues/256))
 - haven't tested on various C++ smart pointers yet
 - haven't tested on inline functions (e.g., explicitly 'inline' or implicitly inlined member functions defined within class definitions, etc)