feat: support zh_CN translate

.editorconfig

@@ -24,7 +24,7 @@ indent_size = 2
 max_line_length = 150
 
 # Ignore paths
-[{.git/**/*,LICENSE,**/Move.lock,mdbook-admonish.css,theme/**/*}]
+[{.git/**/*,LICENSE,**/Move.lock,mdbook-admonish.css,theme/**/*,po/*}]
 charset = unset
 end_of_line = unset
 indent_size = unset

.gitignore

@@ -23,6 +23,7 @@ __pycache__/
 config.yml
 working_dir
 *.log
+*~
 
 # Walrus binary and configuration
 walrus

README.md

@@ -18,9 +18,24 @@ You can also build and access the documentation locally (assuming you have Rust
 cargo install mdbook
 cargo install [email protected] --locked
 cargo install [email protected] --locked
+cargo install mdbook-i18n-helpers --locked
 mdbook serve
 ```
 
+### Using translated versions
+
+If there is a translated resource in `po/` directory, it can be specified through the
+`MDBOOK_BOOK__LANGUAGE` environment variable. For example, to build or serve the Chinese
+translation:
+
+```bash
+MDBOOK_BOOK__LANGUAGE=zh_CN mdbook build
+MDBOOK_BOOK__LANGUAGE=zh_CN mdbook serve
+```
+
+Please consult [TRANSLATING.md](./TRANSLATING.md) for further information on how to create and
+maintain translations.
+
 ## Get help and report issues
 
 If you have general questions or require help on how to use Walrus, please check for [existing

TRANSLATING.md

@@ -0,0 +1,52 @@
+# Translation Guidelines
+
+The Walrus documentation uses [mdbook-i18n-helpers] as a translation framework.
+
+## Preparation
+
+The following tools are required:
+
+- GNU gettext utilities (`msgmerge` and `msgcat`)
+- mdbook-i18n-helpers (`cargo install mdbook-i18n-helpers`)
+
+## Creating and updating translations
+
+Please see the [mdbook-i18n-helpers USAGE] file for the detailed usage of mdbook-i18n-helpers.
+We summarize the most important commands below.
+
+### Generating a message template
+
+The generated message template `po/messages.pot` is required to create or update translations.
+
+```bash
+MDBOOK_OUTPUT='{"xgettext": {"pot-file": "messages.pot"}}' mdbook build -d po
+```
+
+### Creating a new translation resource
+
+In the following, replace `xx` by the [ISO 639][iso_639] language code.
+
+```bash
+msginit -i po/messages.pot -l xx -o po/xx.po
+```
+
+### Updating an existing translation resource
+
+```bash
+msgmerge --update po/xx.po po/messages.pot
+```
+
+## Editing translation resources
+
+After generating a translation resource `po/xx.po`, you can write translation messages
+in `msgstr` entry of `po/xx.po`.
+To build a translated book, the following command can be used.
+
+```bash
+MDBOOK_BOOK__LANGUAGE=xx mdbook build
+MDBOOK_BOOK__LANGUAGE=xx mdbook serve
+```
+
+[mdbook-i18n-helpers]: https://github.com/google/mdbook-i18n-helpers
+[mdbook-i18n-helpers USAGE]: https://github.com/google/mdbook-i18n-helpers/blob/main/i18n-helpers
+[iso_639]: https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes

book.toml

@@ -7,6 +7,7 @@ title = "Walrus"
 
 [build]
 build-dir = "build"
+extra-watch-dirs = ["po"]
 
 [output.html]
 theme = "theme"
@@ -34,3 +35,6 @@ assets_version = "3.0.2" # do not edit: managed by `mdbook-admonish install`
 # Using `\(` and `\)` for inline math and `\[` and `\]` for math blocks.
 block-delimiter = { left = "\\[", right = "\\]" }
 inline-delimiter = { left = "\\(", right = "\\)" }
+
+[preprocessor.gettext]
+after = ["links"]