Init files, made some base constructs

hw6/task2/src/shell.rs

+struct Shell<R, W> {
+    pub reader: R,
+    pub writer: W,
+    pub should_exit: bool,
+    pub name: String,
+}
+
+impl Shell<R, W> {
+    pub fn new(input: R, output: W, name: String) -> Self {
+        Shell {
+            reader = input,
+            writer = output,
+            name = name,
+        }
+    }
+}
+
+impl BufRead for Shell<R, W> {
+}
+
+impl Write for Shell<R, W> {
+    fn write(&mut self, buf: &[u8]) -> Result<usize> {}
+    fn flush(&mut self) -> Result<()> {}
+    fn write_all(&mut self, buf: &[u8]) -> Result<()> {}
+    fn write_format(&mut self, fmt: Arguments) -> Result<()> {}
+    fn by_ref(&mut self) -> &mut Self where Self: Sized, {}
+}
+
+
+let mut s = Shell::new();
+    match s.start() {
+        Ok(_) => process::exit(0),
+        Err(_) => process::exit(1),
+    }