Merge pull request #688 from ember-learn/deprecation-ember-string-loc

Introduce `loc` deprecation

Author: locks

content/ember/v3/deprecate-ember-string-loc.md

@@ -0,0 +1,14 @@
+---
+id: ember-string.loc
+title: Deprecate `@ember/string#loc` and `{{loc}}`
+until: '4.0.0'
+since: 'Upcoming Features'
+---
+
+Ember provides a very basic localization method via the `@ember/string` package `loc` function, and the related `{{loc}}` template helper.
+
+This feature was introduced a long time ago but is insufficient for most use cases.
+We suggest you replace it with an addon in the [Internationalization category](https://emberobserver.com/categories/internationalization) of Ember Observer.
+
+A popular addon that supports [ICU (International Components for Unicode)](http://userguide.icu-project.org/formatparse/messages) message syntax and native browser Intl is [ember-intl](https://ember-intl.github.io/ember-intl/).
+Check the [documentation](https://ember-intl.github.io/ember-intl/docs) for more detailed information.