developer: add localization contribution guide

docs/developer/index.md

@@ -20,6 +20,7 @@ their needs.
   - [code.forgejo.org](./code-forgejo-org/)
   - [next.forgejo.org](./next-forgejo-org/)
   - [Forgejo runner implementation notes](https://code.forgejo.org/forgejo/runner/#hacking)
+  - [Localization](./localization/)
 - For maintainers
   - [Hardware infrastructure](./infrastructure/)
   - [Release management](./release/)

docs/developer/localization.md

@@ -0,0 +1,69 @@
+---
+title: Localization
+license: 'CC-BY-SA-4.0'
+---
+
+Forgejo is translated via Weblate - libre web-based translation platform.
+
+## Translating via Weblate
+
+The Weblate project of Forgejo localization is publicly available at [Codeberg Translate](https://translate.codeberg.org/projects/forgejo/forgejo/) Weblate instance.
+
+### Translation guidelines
+
+1. Please only suggest changes that will benefit all potential users of the translation. Do not suggest changes that will only make the translation better in cases specific to you or your Forgejo instance. Instead you can customize your instance separately from Forgejo upstream.
+2. Try to keep the translation beginner-friendly.
+3. Remember that you're not obligated to do the translation. If you're unsure about translation, feel free to leave it for somebody else to translate later.
+
+### Discovering the translation
+
+Go to the [Project](https://translate.codeberg.org/projects/forgejo/forgejo/) page. You'll see the list of languages that are currently available for translation. Click on your language.
+
+From the language page you can browse all translation strings, as well as untranslated, unfinished and failing ones.
+
+### Suggesting changes
+
+You can suggest changes and additions to the existing translation anonymously: find the string for which you want to suggest a change, type your change in, and click "Suggest". Your change will be checked by a team member for your language before being accepted. Most contributors are volunteers, this can take a while.
+
+### Accepting suggestions, making direct changes
+
+To prevent spam and trolling, direct translations are limited to Forgejo Localization team members.
+
+Being team member, you can use the "Save" button to update the translation directly. You can also apply existing suggestions by clicking the checkmark icon, or reject, optionally specifying the rejection reason.
+
+### Adding a new language
+
+If your language is not available in the language list, you must add first it before translating.
+
+You need to be a Localization team member to add new language. If you're not, please apply! If there's no team member for your language, nobody will be able to check and accept your translations.
+
+### E-mail privacy
+
+By default, Weblate will use your primary e-mail address for your contributions. If you want to adjust this behavior, go to [Weblate settings - Account](https://translate.codeberg.org/accounts/profile/#account) and select a different e-mail under "Commit e-mail" section. You can select `@users.noreply.translate.codeberg.org` address to avoid using any real e-mail address.
+
+## Joining the Localization team
+
+If you want to make direct changes, accept other's suggestions or start a new translation - consider becoming a part of the localization team.
+
+There are two ways available to apply to the team:
+
+- open a new issue at [forgejo/governance](https://codeberg.org/forgejo/governance) repository
+- join the [Matrix room](https://matrix.to/#/#forgejo-localization:matrix.org) and send your application message here
+
+In your application message, please include:
+
+- your motivation for becoming a member
+- your experience at translating other projects and using Weblate. e.g. link(s) to your public translation profile(s) or contributions
+
+Please apply to the team only if you want your actions as a team member to be beneficial to all translation users. Do not apply to make changes that will only benefit you.
+
+To be able to become a member, you'll need a [Codeberg](https://codeberg.org/) account. Then you can use it to log into [Codeberg Translate](https://translate.codeberg.org/).
+
+## Troubleshooting
+
+If you have problems using Weblate, there are multiple support channels available:
+
+- [Weblate documentation](https://docs.weblate.org)
+- [Weblate issues](https://github.com/WeblateOrg/weblate/issues)
+- [Codeberg Translate chat room](https://matrix.to/#/#codeberg-translate:bubu1.eu)
+- [Codeberg community issues](https://codeberg.org/Codeberg/Community/issues)