Update README.md for translate-widget

[ReporterNV]

The widget now uses a solution from IBM, the README.md file is still for Yandex.

И можно ли писать issue не только на английском языке?

[streetturtle]

Good catch, thanks! I completely forgot about it.
I'll leave here some details, just for reference:

awful.key({ modkey }, "c", 
        function() translate.launch{
            api_key = '<api-key>',
            url = 'url'
        } end,
        { description = "run translate prompt", group = "launcher" })

api-key should be generated on this page: https://cloud.ibm.com/iam/apikeys
url should be taken from the Language-Translator's page

[streetturtle]

Done! Thanks again for letting me know! Сорян в общем =)