Fix typo in exercise 6 problem 1 (#136)

Author: FrancescoAiello01

exercises/06.state-initializers/01.problem.initial/README.mdx

@@ -6,7 +6,7 @@
 and reset to the initial state.
 
 🧝‍♂️ I've updated the toggle component to use a reducer instead of `useState`. If
-you'd like to back up, and do that yourself in the playground, by my guest. Or
+you'd like to back up, and do that yourself in the playground, be my guest. Or
 you can <PrevDiffLink>check my work</PrevDiffLink> instead.
 
 👨‍💼 Please add a case in our reducer for the `reset` logic, and add an option to