Fix typo.

exercises/exercise-runtimeparams/README.md

@@ -66,7 +66,7 @@ values[Indices::conti0EqIdx + FluidSystem::H2OIdx] = 0.0;
 This parameter may need to change, and if we choose to always change this within the class,
 we will need to recompile every time.
 
-Instead of hard defining this parameter within the funciton, we can set a variable to read into our parameter tree via the input file and use this in our function instead.
+Instead of hard defining this parameter within the function, we can set a variable to read into our parameter tree via the input file and use this in our function instead.
 To do this, there are two functions defined in `dumux/dumux/common/parameters.hh`, `getParam()` and `getParamFromGroup()`.  They use the following format:
 
 ```c++