docs(angular): add locales-id content (#6944)

src/data/roadmaps/angular/content/locales-by-id@dVKl3Z2Rnf6IB064v19Mi.md

@@ -1 +1,10 @@
 # Locales by ID
+
+Angular uses the Unicode locale identifier (Unicode locale ID) to find the correct locale data for internationalization of text strings. A locale ID specifies the language, country, and an optional code for further variants or subdivisions. A locale ID consists of the language identifier, a hyphen (-) character, and the locale extension. By default, Angular uses `en-US` as the source locale of your project.
+
+Visit the following resources to learn more:
+
+- [@official@Angular Official Docs - Refer to locales by ID](https://angular.dev/guide/i18n/locale-id)
+- [@opensource@Angular locales](https://github.com/angular/angular/tree/main/packages/common/locales)
+- [@official@Codes arranged alphabetically by alpha-3/ISO 639-2 Code](https://www.loc.gov/standards/iso639-2/php/code_list.php)
+- [@official@Unicode CLDR Specifications](https://cldr.unicode.org/index/cldr-spec)