Docs: add Zensical documentation to doctools (#12606)

Create a small page to communicate that Zensical is supported in Read
the Docs and add a small example.

Closes readthedocs/addons#649

---------

Co-authored-by: Eric Holscher <25510+ericholscher@users.noreply.github.com>

Author: humitos

common

@@ -24,6 +24,16 @@ Below is a list of popular documentation tools that you can use to write your do
         Written in
              :bdg-info:`python`
 
+    .. grid-item-card::  Zensical
+        :link: zensical.html
+
+        Zensical is a static-site generator built by the creators of Material for MkDocs.
+
+        Supported formats
+             :bdg-success:`md`
+        Written in
+             :bdg-info:`rust` :bdg-info:`python`
+
     .. grid-item-card::  Sphinx
         :link: sphinx.html
 
@@ -107,4 +117,5 @@ Below is a list of popular documentation tools that you can use to write your do
    /intro/mdbook
    /intro/vitepress
    /intro/antora
+   /intro/zensical
    /intro/mystmd

docs/user/intro/doctools.rst

@@ -0,0 +1,88 @@
+Deploying Zensical on Read the Docs
+===================================
+
+.. meta::
+   :description lang=en: Learn how to host Zensical sites on Read the Docs.
+
+Zensical_ is a modern static site generator designed to simplify building and
+maintaining project documentation. It's built by the creators of Material for MkDocs
+and shares the same core design principles and philosophy – batteries included,
+easy to use, with powerful customization options.
+
+Minimal configuration is required to build an existing Zensical project on Read the Docs:
+
+.. code-block:: yaml
+   :caption: .readthedocs.yaml
+
+    version: 2
+
+    build:
+    os: ubuntu-24.04
+    tools:
+        python: latest
+    jobs:
+      # We recommend using a requirements file for reproducible builds.
+      # This is just a quick example to get started.
+      # https://docs.readthedocs.io/page/guides/reproducible-builds.html
+      install:
+        - pip install zensical
+      build:
+        html:
+          - zensical build
+      post_build:
+        - mkdir -p $READTHEDOCS_OUTPUT/html/
+        - cp --recursive site/* $READTHEDOCS_OUTPUT/html/
+
+.. _Zensical: https://zensical.org/
+
+Quick start
+-----------
+
+- If you have an existing Zensical project you want to host on Read the Docs, check out our :doc:`/intro/add-project` guide.
+- If you're new to Zensical, check out the official `Getting Started <https://zensical.org/docs/get-started/>`_ guide.
+
+Configuring Zensical and Read the Docs Addons
+---------------------------------------------
+
+There are some additional steps you can take to configure your Zensical project to work better with Read the Docs.
+
+.. contents::
+   :local:
+   :backlinks: none
+
+Set the canonical URL
+~~~~~~~~~~~~~~~~~~~~~
+
+A :doc:`canonical URL </canonical-urls>` allows you to specify the preferred version of a web page
+to prevent duplicated content.
+
+Set your Zensical `site URL`_ to your Read the Docs canonical URL using a
+:doc:`Read the Docs environment variable </reference/environment-variables>`:
+
+.. code-block:: toml
+    :caption: zensical.toml
+
+    [project]
+    # Note: variable interpolation is not yet supported in Zensical configuration files,
+    # so you can use the explicit value for now.
+    site_url = "https://your-project.readthedocs.io/"
+
+.. _site URL: https://zensical.org/docs/setup/basics/#site_url
+
+Example repository and demo
+---------------------------
+
+Example repository
+    https://github.com/readthedocs/test-builds/tree/zensical
+
+Demo
+    https://test-builds.readthedocs.io/en/zensical/
+
+Further reading
+---------------
+
+* `Zensical documentation`_
+* `Markdown syntax guide`_
+
+.. _Zensical documentation: https://zensical.org/
+.. _Markdown syntax guide: https://daringfireball.net/projects/markdown/syntax