feat: obliterate type KeySpace

Treating a space differently from other runes was proving to cause more
confusion that clarity.

key.go

@@ -198,7 +198,6 @@ const (
 	KeyPgUp
 	KeyPgDown
 	KeyDelete
-	KeySpace
 	KeyCtrlUp
 	KeyCtrlDown
 	KeyCtrlRight
@@ -275,7 +274,6 @@ var keyNames = map[KeyType]string{
 	KeyUp:             "up",
 	KeyDown:           "down",
 	KeyRight:          "right",
-	KeySpace:          " ", // for backwards compatibility
 	KeyLeft:           "left",
 	KeyShiftTab:       "shift+tab",
 	KeyHome:           "home",
@@ -554,14 +552,6 @@ func readInputs(input io.Reader) ([]Msg, error) {
 		}, nil
 	}
 
-	// If it's a space, override the type with KeySpace (but still include the
-	// rune).
-	if runes[0] == ' ' {
-		return []Msg{
-			KeyMsg(Key{Type: KeySpace, Runes: runes}),
-		}, nil
-	}
-
 	// Welp, it's just a regular, ol' single rune.
 	return []Msg{
 		KeyMsg(Key{Type: KeyRunes, Runes: runes}),