update translating readme

po/README_TRANSLATORS.md

@@ -131,14 +131,18 @@ which should be filled in accordingly. You can then add your translations
 within the newly created translation file.
 
 Afterwards, you need to update the list of known locales within Ghostty's
-build system. To do so, open `src/build/GhosttyI18n.zig` and find the list
-of locales under the `locale` variable, then append the full locale name
+build system. To do so, open `src/os/i81n.zig` and find the list
+of locales under the `locales` variable, then add the full locale name
 into the list.
 
+The order matters, so make sure to place your locale in the correct position.
+Read the comment above the variable for more details on the order. If you're
+unsure, place it at the end of the list.
+
 ```zig
 const locales = [_][]const u8{
     "zh_CN.UTF-8",
-    // <- Add your locale here
+    // <- Add your locale here (probably)
 }
 ```
 

src/os/i18n.zig

@@ -11,6 +11,17 @@ const log = std.log.scoped(.i18n);
 /// a language code available), the first match is used. For example, if
 /// we know the user requested `zh` but has no region code, then we'd pick
 /// the first locale that matches `zh`.
+///
+/// For ordering, we prefer:
+///
+///   1. The most common locales first, since there are places in the code
+///      where we do linear searches for a locale and we want to minimize
+///      the number of iterations for the common case.
+///
+///   2. Alphabetical for otherwise equally common locales.
+///
+///   3. Most preferred locale for a language without a country code.
+///
 pub const locales = [_][:0]const u8{
     "zh_CN.UTF-8",
 };