Improve GUI -> About helptext [formatting, update]

[giantclambake]

This helptext needs updating, to bring it inline with wiki content, including descriptions of buttons.

Most all of this lifted from wiki/GUI:-About, with the usual wording changes to make things fit.

As usual, please review.

TIA

For.... src/osdep/gui/PanelAbout.cpp

bool HelpPanelAbout(std::vector<std::string>& helptext)
{
        helptext.clear();
        helptext.emplace_back("This panel contains information about the version of Amiberry, when it was changed,");
        helptext.emplace_back("which version of SDL2 it was compiled against and currently using.");
        helptext.emplace_back(" ");
        helptext.emplace_back("Furthermore, you can also find the GPLv3 license notice here, and if you scroll down");
        helptext.emplace_back("all the credits to the people behind the development of this emulator as well.");
        helptext.emplace_back(" ");
        helptext.emplace_back("At the bottom of the screen, there are a few buttons available regardless of which");
        helptext.emplace_back("panel you have selected. Those are: ");
        helptext.emplace_back(" ");
        helptext.emplace_back("\"Shutdown\": allows you to shutdown the whole system Amiberry is running on. This");
        helptext.emplace_back(" option can be disabled if you wish, by setting \'disable_shutdown_button=yes\' in");
        helptext.emplace_back(" in your amiberry.conf file.");
        helptext.emplace_back(" ");
        helptext.emplace_back("\"Quit\": This quits Amiberry, as you'd expect.");
        helptext.emplace_back(" ");
        helptext.emplace_back("\"Restart\": This button will stop emulation (if running), reload Amiberry and reset");
        helptext.emplace_back(" the configuration. This has a similar effect as if you Quit and start Amiberry again.");
        helptext.emplace_back(" It can be useful if you want to change a setting that cannot be changed on-the-fly,");
        helptext.emplace_back(" and you don't want to quit and start the Amiberry again to do that.");
        helptext.emplace_back(" ");
        helptext.emplace_back("\"Help\": This will display some on-screen help/documentation, relating to the Panel");
        helptext.emplace_back(" you are currently in.");
        helptext.emplace_back(" ");
        helptext.emplace_back("\"Reset\": This button will trigger a hard reset of the emulation, which will reboot");
        helptext.emplace_back(" with the current settings. ");
        helptext.emplace_back(" ");
        helptext.emplace_back("\"Start\": This button starts the emulation, using the current settings you have set.");
        helptext.emplace_back(" ");
        return true;
}

[midwan]

Thanks, updated