Limit globe button visibility to /keyboards/ pages 🗺️

[darcywong00]

Addresses this point of #384

We should hide the icon on pages that don't have localization (to avoid disappointment for users)

Will limit visibility to /keyboards/ pages

Test-bot: skip

[keymanapp-test-bot]

User Test Results

Test specification and instructions

User tests are not required

[mcdurdin]

I'd prefer to bake this into the infrastructure. My proposal:

Add this to Locale class:

    /**
     * Defines a global variable for page locale strings and also
     * tells locale system that current page uses locales
     */
    public static function definePageLocale($define, $id) {
      global $page_is_using_locale;
      $page_is_using_locale = true;
      define($define, $id);
    }

Use this test in render_globe_dropdown:

        global $page_is_using_locale;
        if(!isset($page_is_using_locale) || !$page_is_using_locale) {
          // only render on pages that use localized strings
          return;
        }

And in each page, remove the define('LOCALE... line and replace it with the equivalent of:

  Locale::definePageLocale('LOCALE_KEYBOARDS', 'keyboards');

[darcywong00]

I'd prefer to bake this into the infrastructure. My proposal:

Got it. I'll update #623 separately (install and share pages) once this gets merged

[mcdurdin]

LGTM 😉