Implement i18n translations

[circlecube]

The default text strings are set up for translation strings.

The module needs a .pot file and associated .po, .mo and .json files for translations. The strings likely have pt_BR and es_MX translations already thanks to the Hostgator Plugin.

The module needs to contain the translations as well as load them for the module specific text-domain: wp-module-performance or update the text-domain to something newfold specific like newfold-wp-module-performance.

Refer to the onboarding module which has translations in place here: newfold-labs/wp-module-onboarding#299