docs: migrate to MkDocs, fixes #1046

Author: ken-matsui

.github/workflows/docs.yml

@@ -0,0 +1,18 @@
+name: Docs
+
+on:
+  push:
+    branches: [main]
+
+jobs:
+  build-and-deploy:
+    name: "build & deploy"
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Deploy docs
+        uses: mhausenblas/mkdocs-deploy-gh-pages@nomaterial
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          CUSTOM_DOMAIN: docs.poac.dev

docs/CNAME

@@ -1,4 +1,4 @@
-## Acknowledgements
+# Acknowledgements
 
 This project exists thanks to all the people who contribute.
 

docs/_config.yml

@@ -1,8 +1,9 @@
 ---
-layout: default
-title: 4. Hello, World!
+title: Hello, World!
 ---
 
+# Hello, World!
+
 You can get started with just a few commands as the demo shows. Let's create a new Poac project:
 
 ```console

docs/acknowledgements.md

@@ -1,7 +1,7 @@
 ---
-layout: default
-title: 1. Introduction
-permalink: /
+title: Introduction
 ---
 
+# Introduction
+
 Poac (pronounced as `/pəʊək/`) is a package manager and build system for C++ users, inspired by Cargo for Rust.  Poac is designed as a structure-oriented build system, which means that as long as you follow Poac's designated project structure, you almost do not need configurations, much less a language to build, unlike CMake.  If you do not like writing a bunch of configurations to build your project, Poac might be best suited.  Currently, the supported project structure can be known by looking at this repository since Poac can build itself.

docs/hello-world.md

@@ -1,7 +1,4 @@
----
-layout: default
-title: 3. Installation
----
+# Installation
 
 [![Packaging status](https://repology.org/badge/vertical-allrepos/poac.svg)](https://repology.org/project/poac/versions)
 

docs/README.md docs/index.mddocs/README.md renamed to docs/index.md

@@ -1,7 +1,8 @@
 ---
-layout: default
-title: 6. Package Layout
+title: Package Layout
 ---
 
+# Package Layout
+
 * `src/**`: contains source files and private header files
 * `include/**`: contains public header files

docs/installation.md

@@ -1,7 +1,4 @@
----
-layout: default
-title: 5. Usage
----
+# Usage
 
 ## Start a new project with Poac
 

docs/package-layout.md

@@ -1,8 +1,9 @@
 ---
-layout: default
-title: 2. Why Poac?
+title: Why Poac?
 ---
 
+# Why Poac?
+
 C++ is often considered a complex language and unconsciously avoided by many.  The absence of a definitive package manager and the unfamiliar syntax of build systems like [CMake](https://cmake.org) make it seem difficult to set up a C++ environment, leaving people hesitant.
 
 To simplify the process and allow users to develop applications and libraries without worrying about [CMake](https://cmake.org), I created a package manager and build system with an intuitive interface, similar to [Cargo](https://github.com/rust-lang/cargo). This allows developers to focus on learning C++ without any hindrances. Additionally, I aim to integrate with other build systems and package managers, providing a seamless transition between development environments.
@@ -15,4 +16,4 @@ Poac is originated from `cpp` but designed to prioritize ease of typing and redu
 
 Despite C++ often being overlooked for product development, I believe that Poac can help to promote it as a fun language. Amemiya and Mizutani argue that the sound of `/p/` is associated with a bright and soft impression among Japanese consonants (157)[^1]. In the same way, I believe that Poac's name can convey a similarly positive impression.
 
-[^1]: Amemiya, T., & Mizutani, S. (2006). On the Basic Affective Dimensions of Japanese Onomatopoeia and the Basic Level of Japanese Phonesthemes. 関西大学社会学部紀要, 37(2), 139–166. https://hdl.handle.net/10112/12311
+[^1]: Amemiya, T., & Mizutani, S. (2006). On the Basic Affective Dimensions of Japanese Onomatopoeia and the Basic Level of Japanese Phonesthemes. 関西大学社会学部紀要, 37(2), 139–166. <https://hdl.handle.net/10112/12311>