Added Hide GUI Keybind (#62)

F1 to hide gui
Also renamed the field for hiding the GUI to m_bDontRenderGui

I would have named it m_bRenderGui and flipped the default values and checks but I assumed that changing the least amount of stuff would be desired.

source/common/Options.cpp

@@ -29,7 +29,7 @@ void Options::initDefaultValues()
 {
 	field_238 = 2;
 	field_244 = 1.0f;
-	field_23C = 0;
+	m_bDontRenderGui = false;
 	field_248 = 1.0f;
 	m_bThirdPerson = false;
 	field_0   = 1.0f;

source/common/Options.hpp

@@ -101,7 +101,7 @@ public:
 	KeyBind m_keyBinds[16];
 
 	int field_238;
-	uint8_t field_23C;
+	bool m_bDontRenderGui;
 	bool m_bThirdPerson;
 	uint8_t field_23E;
 	bool m_bFlyCheat;