fix: lazysecrets starts from fzf's become, on a non-blocking terminal (#67)

fzf's become hands lazysecrets its /dev/tty still non-blocking. Go can't poll /dev/tty on macOS, so it reads it directly, and the TUI's first read failed with "resource temporarily unavailable" (EAGAIN). lazysecrets now makes a terminal on stdin blocking before the TUI starts (Unix; nothing on Windows).

Reviewed-on: #67
Co-authored-by: Karl-Einar Bergstrøm <karl-einarb@outlook.com>

cmd/lazysecrets/main.go

@@ -436,6 +436,7 @@ Flags:
 		Styles:         &theme,
 		DefaultFg:      defaultFg,
 	})
+	blockingStdin()
 	p = tea.NewProgram(m)
 	final, err := p.Run()
 	if fm, ok := final.(app.Model); ok {