feat: support zh_CN translate

.gitignore

@@ -30,3 +30,6 @@ walrus
 examples/CONFIG/bin/walrus
 ./client_config.yaml
 examples/CONFIG/config_dir/client_config.yaml
+
+book/
+po/*.po~

README.md

@@ -18,9 +18,19 @@ 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 version
+
+If there is a translated resource in `po/` directory, it can be specified through `MDBOOK_BOOK__LANGUAGE` like below:
+
+```bash
+MDBOOK_BOOK__LANGUAGE=zh_CN mdbook build
+MDBOOK_BOOK__LANGUAGE=zh_CN mdbook serve
+```
+
 ## 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 +1,49 @@
+# Translation Guidelines
+
+## Translation workflow
+
+### Preparation
+
+RBE uses [mdbook-i18n-helpers](https://github.com/google/mdbook-i18n-helpers) as a translation framework.
+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](https://github.com/google/mdbook-i18n-helpers/blob/main/i18n-helpers/USAGE.md) file for the detailed usage of mdbook-i18n-helpers.
+The summarized command list is below:
+
+#### Generating a message template
+
+The generated message templete `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
+
+`xx` is [ISO 639](https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes) language code.
+
+```bash
+msginit -i po/messages.pot -l xx -o po/xx.po
+```
+
+#### Updating the 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
+```

book.toml

@@ -6,7 +6,8 @@ src = "docs"
 title = "Walrus"
 
 [build]
-build-dir = "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"]