Supporting a button library.

libraries/button/library.toml

@@ -0,0 +1,15 @@
+[library]
+name = "button"
+version = "0.1.0"
+description = "Momentary pushbutton with debounce support"
+
+[requires]
+bus = "digital"
+pins = ["signal"]
+
+[provides]
+interface = "button.h"
+implementation = "button_digital.h"
+mock = "button_mock.h"
+simulation = "button_sim.h"
+test = "test_button.cpp"