fix: improve Dockerfile for international contributors (#1861)

* fix: improve Dockerfile for international contributors

- Upgrade base image from python:3.10.0-alpine to python:3.12-alpine
  for security patches
- Replace hardcoded Chinese PyPI mirror with configurable ARG defaulting
  to official PyPI (Chinese users can override via --build-arg)
- Add missing Japanese docs build step

Co-Authored-By: claude-flow <ruv@ruv.net>

* Change Python base image and add Russian docs

Updated Python base image from 3.12 to 3.10 and added support for Russian documentation.

---------

Co-authored-by: Santosh Maturi <santhum@amazon.com>
Co-authored-by: claude-flow <ruv@ruv.net>
Co-authored-by: Yudong Jin <krahets@163.com>

Dockerfile

@@ -1,6 +1,11 @@
 FROM python:3.10.0-alpine
 
-ENV PIP_INDEX_URL=https://pypi.tuna.tsinghua.edu.cn/simple
+# Official PyPI is preferred when reachable.
+ENV PIP_INDEX_URL=https://pypi.org/simple
+
+# Use the mirror when official PyPI is unreachable.
+# ENV PIP_INDEX_URL=https://pypi.tuna.tsinghua.edu.cn/simple
+
 RUN pip install --upgrade pip
 RUN pip install mkdocs-material==9.5.5 mkdocs-glightbox
 
@@ -20,6 +25,14 @@ COPY en/docs ./build/en/docs
 COPY en/mkdocs.yml ./en/mkdocs.yml
 RUN mkdocs build -f ./en/mkdocs.yml
 
+COPY ja/docs ./build/ja/docs
+COPY ja/mkdocs.yml ./ja/mkdocs.yml
+RUN mkdocs build -f ./ja/mkdocs.yml
+
+COPY ru/docs ./build/ru/docs
+COPY ru/mkdocs.yml ./ru/mkdocs.yml
+RUN mkdocs build -f ./ru/mkdocs.yml
+
 WORKDIR /hello-algo/site
 EXPOSE 8000
 CMD ["python", "-m", "http.server", "8000"]