Fix Typo

docs/simple_flight.md

@@ -12,7 +12,7 @@ The advantage of using simple_flight is zero additional setup you need to do and
 
 Normally flight controllers are designed to run on actual hardware on vehicles and their support for running in simulator varies widely. They are often fairly difficult to configure for non-expert users and typically have complex build usually lacking cross platform support. All these problems have played significant part in design of simple_flight.
 
-simple_slight is designed from ground up as library with clean interface that can work onboard the vehicle as well as simulator. The core principle is that flight controller has no way to specify special simulation mode and there for it has no way to know if it is running under simulation or real vehicle. We thus view flight controller simply as collection of algorithms packaged in a library. Another key emphasis is to develop this code as dependency free header-only pure standard C++11 code. This means there is no special build required to compile simple_flight. You just copy its source code to any project you wish and it just works.
+simple_flight is designed from ground up as library with clean interface that can work onboard the vehicle as well as simulator. The core principle is that flight controller has no way to specify special simulation mode and there for it has no way to know if it is running under simulation or real vehicle. We thus view flight controller simply as collection of algorithms packaged in a library. Another key emphasis is to develop this code as dependency free header-only pure standard C++11 code. This means there is no special build required to compile simple_flight. You just copy its source code to any project you wish and it just works.
 
 ## Control
 
@@ -70,4 +70,4 @@ Finally, simple_flight uses steppable clock by default which means clock advance
 {
     "ClockType": "ScalableClock"
 }
-```
+```