feat(keyboard): add getkey function

k/pic/keyboard.c

@@ -0,0 +1,13 @@
+#include "pic/keyboard.h"
+#include "io.h"
+#include "stdio.h"
+
+int8_t getkey(void)
+{
+    uint8_t key = inb(KEYBOARD_IO);
+
+    if (key & KEYBOARD_RELEASE)
+        return -1;
+
+    return key;
+}

k/pic/keyboard.h

@@ -0,0 +1,13 @@
+#ifndef KEYBOARD_H
+#define KEYBOARD_H
+
+#define KEYBOARD_IO     0x60
+#define KEYBOARD_STATUS 0x64
+
+#define KEYBOARD_RELEASE 0x80
+
+#include <stdint.h>
+
+int8_t getkey(void);
+
+#endif /* !KEYBOARD_H */