Changes

* Localization: Add-on developers come from many different countries and regions. We’d like to setup the linter to be fully localized in the same list of countries as https://addons.mozilla.org (AMO). See the following issues for an idea for what’s involved https://github.com/mozilla/addons-linter/issues/1535*Migrate to Await/Async - the linter currently makes heavy use of promises. The newer Await/Async syntax makes code easier to read and understand. See the issues for additional details as to what is involved https://github.com/mozilla/addons-linter/issues/1536. This task requires a good understanding of promises and their various nuances.*Improving validation. There’s several areas where the validation the linter currently provides could be improved here’s a few suggested areas to start:<br /># Improve the feedback given to developers about icon usage: See https://github.com/mozilla/addons-linter/labels/component%3A%20icons for more details.# Permissions. The linter could do more to inform the developer of relevant information related to the permissions they have asked for in the manifest.json. See this label for more information https://github.com/mozilla/addons-linter/labels/component%3A%20permissions# Improve issues related to schema validation. See https://github.com/mozilla/addons-linter/labels/component%3A%20schema for more details.