docs: add comprehensive documentation for operations

This commit introduces a complete set of documentation files
covering various aspects of the project, including environment
setup, quality checks, command references, and architecture.
The documentation is structured to assist developers and
contributors in understanding the project's configuration,
workflow, and best practices.

Additionally, translations for Simplified and Traditional
Chinese have been added to ensure accessibility for a wider
audience. This enhances the overall usability and
maintainability of the project.

Signed-off-by: Bertrand Yuan <github@bertyuan.com>

1 files changed, 61 insertions, 0 deletions

diff --git a/Documentation/source/introduction.rst b/Documentation/source/introduction.rst
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+Introduction
+============
+
+Next Blog is a reading-first personal publishing platform. It combines a
+Next.js App Router frontend with Payload CMS for editorial workflows and a
+PostgreSQL-backed application layer for authentication, comments, and related
+state.
+
+Product Scope
+-------------
+
+The current product scope is intentionally focused:
+
+* publish and manage posts through Payload CMS;
+* render public blog pages, tag pages, and post detail pages;
+* support OAuth login through better-auth;
+* allow signed-in users to comment through Fuma Comments;
+* expose RSS, search, metadata, JSON-LD, sitemap, and Open Graph outputs;
+* provide a newsletter form and React Email template for future email flows.
+
+The platform is not a generic community CMS. It is a controlled publishing
+site with a public reading surface and a private admin surface.
+
+Primary Roles
+-------------
+
+.. list-table::
+   :header-rows: 1
+   :widths: 20 34 36
+
+   * - Role
+     - Goal
+     - Main Routes
+   * - Visitor
+     - Browse and read content.
+     - ``/``, ``/posts``, ``/posts/[slug]``, ``/tags``
+   * - Returning reader
+     - Filter by topic and follow updates.
+     - ``/tags/[tag]``, ``/rss.xml``
+   * - Authenticated user
+     - Comment and use account-aware actions.
+     - ``/login``, ``/posts/[slug]``
+   * - Content admin
+     - Create, edit, schedule, and publish content.
+     - ``/admin``
+
+Design Direction
+----------------
+
+The public site should stay content-first: clear hierarchy, low visual noise,
+predictable navigation, and fast access to posts and tags. The existing visual
+language uses dashed borders, corner markers, restrained motion, and system
+theme support.
+
+Documentation Direction
+-----------------------
+
+This Sphinx tree is the canonical documentation system for the repository.
+Short product briefs and research notes can still live in ``docs/`` as raw
+inputs, but durable engineering documentation should be promoted into
+``Documentation/source`` as reStructuredText.