Mention Crowdin in our documentation

CONTRIBUTING.md

@@ -12,6 +12,7 @@ If you've any other questions, [just ask the community][community] or [open an i
 
 ## Table of Contents
  - [Reporting issues](#reporting-issues)
+ - [Translations](#translations)
  - [Setting up a development environment](#setting-up-a-development-environment)
  - [Developing CC: Tweaked](#developing-cc-tweaked)
  - [Writing documentation](#writing-documentation)
@@ -20,6 +21,10 @@ If you've any other questions, [just ask the community][community] or [open an i
 If you have a bug, suggestion, or other feedback, the best thing to do is [file an issue][new-issue]. When doing so, do
 use the issue templates - they provide a useful hint on what information to provide.
 
+## Translations
+Translations are managed through [CrowdIn], an online interface for managing language strings. Translations may either
+be contributed there, or directly via a pull request.
+
 ## Setting up a development environment
 In order to develop CC: Tweaked, you'll need to download the source code and then run it.
 
@@ -102,3 +107,4 @@ about how you can build on that until you've covered everything!
 [busted]: https://github.com/Olivine-Labs/busted "busted: Elegant Lua unit testing."
 [node]: https://nodejs.org/en/ "Node.js"
 [architecture]: projects/ARCHITECTURE.md
+[Crowdin]: https://crowdin.com/project/cc-tweaked/

crowdin.yml

@@ -4,3 +4,23 @@
 files:
   - source: projects/common/src/generated/resources/assets/computercraft/lang/en_us.json
     translation: /projects/common/src/main/resources/assets/computercraft/lang/%locale_with_underscore%.json
+    languages_mapping:
+      locale_with_underscore:
+        cs: cs_cs    # Czech
+        da: da_dk    # Danish
+        de: de_de    # German
+        es-ES: es_es # Spanish
+        fr: fr_fr    # French
+        it: it_it    # Italian
+        ja: ja_jp    # Japanese
+        ko: ko_kr    # Korean
+        nb: nb_no    # Norwegian Bokmal
+        nl: nl_nl    # Dutch
+        pl: pl_pl    # Polish
+        pt-BR: pt_br # Portuguese, Brazilian
+        ru: ru_ru    # Russian
+        sv-SE: sv_se # Sweedish
+        tok: tok     # Toki Pona
+        uk: uk_ua    # Ukraine
+        vi: vi_vn    # Vietnamese
+        zh-CN: zh_cn # Chinese Simplified