docs: add reference to the official Zensical image

# GitLab CI template for MkDocs

This project implements a GitLab CI/CD template to build your static website with [MkDocs](https://www.mkdocs.org/).

Since version 2.11, this template also supports [Zensical](https://zensical.org/docs/get-started/). This tool is highly compatible with MkDocs, particularly Material for MkDocs

, as it was created by the same author.

Since version 2.11, this template also supports [Zensical](https://zensical.org/docs/get-started/). This tool is highly compatible with MkDocs, particularly Material for MkDocs, as it was created by the same author.

## Usage

| `PIP_INDEX_URL` | Python repository url | _none_ |

| `pip-opts` / `PIP_OPTS` | pip extra [options](https://pip.pypa.io/en/stable/cli/pip/#general-options) | _none_ |

:information_source: `MKD_IMAGE`: To use Zensical, you can use `docker.io/squidfunk/mkdocs-material:latest`, or any image with Python (`docker.io/library/python:latest`) or Astral uv (`docker.io/astral/uv:python3.14-trixie-slim`).

:information_source: `MKD_IMAGE`: To use *Zensical*, you may use the official image `docker.io/zensical/zensical:latest`.<br/> :information_source: While you can stay on `docker.io/squidfunk/mkdocs-material:latest` for now, please note that maintenance for this image is scheduled to end. Zensical remains also compatible with any standard Python environment `docker.io/library/python:latest` or Astral uv `docker.io/astral/uv:python3.14-trixie-slim`.

:information_source: `MKDOCS_BUILD_SYSTEM`: When using Zensical, you can specify the build tool version by including a [version identifier](https://peps.python.org/pep-0440/). For example: `MKDOCS_BUILD_SYSTEM="zensical==0.0.10"`.

:information_source: `MKDOCS_BUILD_SYSTEM`: When using *Zensical*, you can specify the build tool version by including a [version identifier](https://peps.python.org/pep-0440/). For example: `MKDOCS_BUILD_SYSTEM="zensical==0.0.10"`.

:warning: Unlike MkDocs, Zensical doesn't require managing Python dependencies. While it currently lacks a component system, most features are built-in.