commit cea6284

Add Alt+A keybinding for jumping to next unread buffer

This is a standard keybinding in irssi and weechat, and was frequently
requested by users. It maps to the existing buffer-next-unread action,
which is also available via Shift+Right.

Fixes: https://todo.sr.ht/~delthas/senpai/236

1@@ -1085,6 +1085,7 @@ var defaultCommands = map[string][]string{
2 	"\r":              {"send"},
3 	"Control+j":       {"send"},
4 	"KP_Enter":        {"send"},
5+	"Alt+a":           {"buffer-next-unread"},
6 	"Alt+n":           {"scroll-next-highlight"},
7 	"Alt+p":           {"scroll-previous-highlight"},
8 	"Alt+1":           {"buffer", "0"},