Use xx-XX format for translation files and default to en-US

Many languages have different variants, so instead of "en" we should be
using "en-US" - this will make it possible to add slightly different
British English translations, for example.
Note that this was already supported for the `locale` config option, we
were simply discarding the part after the dash when looking for the
right translation file.

Also make sure the en-US translations are actually American English,
I'll add en-GB separately.

README.md

@@ -142,7 +142,7 @@ unused i18n entries, run:
 $ yarn i18n:report
 ```
 
-To add a new locale, copy `en.json` to `<locale>.json` in [`src/locales`](src/locales)
+To add a new locale, copy `en-US.json` to `<locale>.json` in [`src/locales`](src/locales)
 and start translating the individual strings. Make sure to [mention the new locale to the docs](docs/config.md#locale)!
 
 For a specific example see commit [`b2edda4`](https://github.com/owntracks/frontend/commit/b2edda410f16633aa6fd9cd4e5250f2031536c7d)

docs/config.md

@@ -171,15 +171,16 @@ formats.
 
 Available languages:
 
-- `de` (German)
-- `en` (English)
-- `es` (Spanish)
-- `fr` (French)
+- `de-DE` (Standard German)
+- `en-US` (American English)
+- `es-ES` (Castilian Spanish)
+- `fr-FR` (Standard French)
 
-You can use formats like `en-GB`, `en-US`, `de-DE`, `fr-FR`.
+Using a locale with non-existent translations is possible and will affect date/time formats, but
+use `en-US` for translations.
 
 - Type: [`String`]
-- Default: `"en"`
+- Default: `"en-US"`
 
 ### `map.attribution`
 

src/config.js

@@ -17,7 +17,7 @@ const DEFAULT_CONFIG = {
     minAccuracy: null,
   },
   ignorePingLocation: true,
-  locale: "en",
+  locale: "en-US",
   map: {
     attribution:
       '&copy; <a href="https://osm.org/copyright">OpenStreetMap</a> contributors',

src/i18n.js

@@ -16,8 +16,8 @@ locales.keys().forEach((key) => {
 });
 
 export default new VueI18n({
-  locale: config.locale.split("-")[0],
-  fallbackLocale: "en",
+  locale: config.locale,
+  fallbackLocale: "en-US",
   formatFallbackMessages: true,
   messages,
 });

src/locales/en-US.json

@@ -10,7 +10,7 @@
   "Select user": "Select user",
   "Show all": "Show all",
   "Select device": "Select device",
-  "Distance travelled": "Distance travelled",
+  "Distance travelled": "Distance traveled",
   "Download raw data": "Download raw data",
   "Information": "Information",
   "Show last known locations": "Show last known locations",