Add new actions to sample bindings file and help screen

doc/bindings

@@ -147,6 +147,8 @@
 ## The following actions are not bound to any key/command:
 ##
 ##  - set_volume
+##  - load
+##  - play
 ##
 #
 #def_key "mouse"

src/screens/help.cpp

@@ -173,6 +173,7 @@ void write_bindings(NC::Scrollpad &w)
 	key(w, Type::ShowServerInfo, "Show server info");
 
 	key_section(w, "Global");
+	key(w, Type::Play, "Play");
 	key(w, Type::Stop, "Stop");
 	key(w, Type::Pause, "Pause");
 	key(w, Type::Next, "Next track");
@@ -247,6 +248,7 @@ void write_bindings(NC::Scrollpad &w)
 	key(w, Type::MoveSelectedItemsDown, "Move selected item(s) down");
 	key(w, Type::MoveSelectedItemsTo, "Move selected item(s) to cursor position");
 	key(w, Type::Add, "Add item to playlist");
+	key(w, Type::Load, "Load stored playlist");
 #	ifdef HAVE_TAGLIB_H
 	key(w, Type::EditSong, "Edit song");
 #	endif // HAVE_TAGLIB_H