Don't treat the space character as a control character

There are drawbacks to both sides of this, but in the end, it seems to make
more sense to treat spaces as regular runes.

key.go

@@ -256,12 +256,6 @@ func ReadKey(r io.Reader) (Key, error) {
 		return Key{Type: KeyType(char)}, nil
 	}
 
-	// If it's a space treat it like a control character (otherwise it gets
-	// treated as the character " "
-	if string(char) == " " {
-		return Key{Type: KeyType(keySP)}, nil
-	}
-
 	// Is it a special sequence, like an arrow key?
 	if k, ok := sequences[string(buf[:numBytes])]; ok {
 		return Key{Type: k}, nil

viewport/viewport.go

@@ -86,7 +86,7 @@ func Update(msg boba.Msg, m Model) (Model, boba.Cmd) {
 		// Down one page
 		case "pgdown":
 			fallthrough
-		case "space":
+		case " ": // spacebar
 			fallthrough
 		case "f":
 			m.ViewDown()