Add language picker for docs (#2403)

.github/workflows/ci.yaml

@@ -14,6 +14,7 @@ defaults:
 
 env:
   RUSTFLAGS: --deny warnings
+  LANGUAGES:
 
 jobs:
   docs:
@@ -34,7 +35,18 @@ jobs:
         chmod +x mdbook-linkcheck
         pwd >> $GITHUB_PATH
 
-    - run: mdbook build docs
+    - name: Build docs
+      run: mdbook build docs -d build
+
+    - name: Build all translations for docs
+      run: |
+        for lang in ${{ env.LANGUAGES }}; do
+          echo "::group::Building $lang translation"
+          MDBOOK_BOOK__LANGUAGE=$lang \
+            mdbook build docs -d build/$lang
+          mv docs/build/$lang/html docs/build/html/$lang
+          echo "::endgroup::"
+        done
 
     - name: Deploy Pages
       uses: peaceiris/actions-gh-pages@v3
@@ -43,6 +55,7 @@ jobs:
         github_token: ${{secrets.GITHUB_TOKEN}}
         publish_branch: gh-pages
         publish_dir: docs/build/html
+
   lint:
     runs-on: ubuntu-latest
 

README.md

@@ -236,3 +236,15 @@ Release x.y.z
 - Update dependencies
 - Update database schema version
 ```
+
+Translations
+------------
+
+To translate [the docs](https://docs.ordinals.com) we use this
+[mdBook i18n helper](https://github.com/google/mdbook-i18n-helpers).
+So read through their [usage guide](https://github.com/google/mdbook-i18n-helpers/blob/main/USAGE.md)
+to see the structure that translations should follow.
+
+There are some other things to watch out for but feel free to just start a
+translation and open a PR. A maintainer will then help you integrate it into our
+build system.

docs/book.toml

@@ -6,11 +6,16 @@ src = "src"
 [build]
 build-dir = "build"
 create-missing = false
+extra-watch-dirs = ["po"]
 
 [output.html]
 cname = "docs.ordinals.com"
 default-theme = "coal"
 git-repository-url = "https://github.com/ordinals/ord"
 preferred-dark-theme = "coal"
+additional-css = ["language-picker.css"]
 
 [output.linkcheck]
+
+[preprocessor.gettext]
+after = ["links"]

docs/language-picker.css

@@ -0,0 +1,8 @@
+#language-list {
+  left: auto;
+  right: 10px;
+}
+
+#language-list a {
+  color: inherit;
+}