UART write example (#53)

* Rename test functions

* rewrite furi API, segfault

* make fixes in FURI, log through FURI

* add uart write example blank

* implement fuprintf instead of fopencookie

* add gif, blank page

* UART write example description

Co-authored-by: Vadim Kaushan <admin@disasm.info>

core/tty_uart.h

@@ -0,0 +1,5 @@
+#pragma once
+
+#include <stdbool.h>
+
+bool register_tty_uart();