feat: streams, 'clear' command

src/program/clear.ts

@@ -0,0 +1,7 @@
+import type { SimpleStream } from '../utils/SimpleStream'
+
+export const ClearExec = async (stdin: SimpleStream<string>, stdout: SimpleStream<string>): Promise<number> => {
+    stdout.emit("\f")
+
+    return 0
+}