Fix SessionResponse typo (#67)

Author: danroth27

docs/2. Build out BackEnd and Refactor.md

@@ -583,7 +583,7 @@ Okay, now we need to update our `ApplicationDbContext` so Entity Framework knows
 ## Adding the remaining API Controllers
 1. Add the following response DTO classes from [the save point folder](/save-points/2b-BackEnd-completed/ConferencePlanner/ConferenceDTO)
    - `AttendeeResponse`
-   - `SessionRespsone`
+   - `SessionResponse`
    - `ConferenceResponse`
    - `TrackResponse`
    - `TagResponse`