Update docs/src/basics/InputOutput.md

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

Author: ChrisRackauckas

docs/src/basics/InputOutput.md

@@ -54,6 +54,7 @@ We can inspect the state realization chosen by MTK
 x_sym
 ```
 
+as expected, `x` is chosen as the state variable.
 as expected, `x` is chosen as the state variable.
 
 ```@example inputoutput