Add deployment guide and fix stale README theme listing

- Create guide.md: step-by-step deployment guide in ProjectPublic
  markup format, written for non-technical users
- Add guide-format.txt: markup syntax reference
- Fix README.md: remove references to deleted templates/ and parts/
  directories in theme tree listing

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

guide-format.txt

@@ -0,0 +1,141 @@
+ ProjectPublic Markup Syntax — Complete Reference
+
+  Document Structure
+
+  Every document has two parts: frontmatter (metadata) and steps (content).
+
+  Frontmatter
+
+  Must be the first thing in the document, delimited by ---:
+
+  ---
+  title: Your Project Title Here
+  summary: A brief 1-2 sentence description of what this guide covers
+  tags: Docker, Linux, Networking
+  difficulty: beginner
+  time: 45 minutes
+  prerequisites: Basic Linux knowledge, SSH access
+  video: https://youtube.com/watch?v=example
+  ---
+
+  Required fields:
+  - title — project title (max 120 chars)
+  - summary — short description (max 280 chars)
+  - tags — comma-separated list (at least 1)
+  - difficulty — one of: beginner, intermediate, advanced
+
+  Optional fields:
+  - time — estimated time (e.g., "45 minutes", "2 hours")
+  - prerequisites — comma-separated list
+  - video — URL to an accompanying video
+
+  Steps
+
+  Each step starts with [step: Step Title] on its own line:
+
+  [step: Install Docker]
+
+  Content goes here...
+
+  [step: Configure the Container]
+
+  More content...
+
+  At least one step is required. Steps are numbered automatically (1, 2, 3...).
+
+  Element Types (within steps)
+
+  1. Text (Markdown)
+
+  Plain text between block tags is treated as Markdown. Supports standard Markdown:
+
+  This is a paragraph with **bold**, *italic*, and `inline code`.
+
+  - Bullet list item
+  - Another item
+
+  1. Numbered list
+  2. Second item
+
+  [Links work like this](https://example.com)
+
+  > Blockquotes work too
+
+  2. Code Block
+
+  [code:bash | install.sh]
+  sudo apt update
+  sudo apt install docker.io
+  systemctl enable --now docker
+  [/code]
+
+  - Syntax: [code:language | filename]...[/code]
+  - language — syntax highlighting language (e.g., bash, python, yaml, json, javascript, dockerfile)
+  - | filename — optional, displayed as a tab/label above the code
+  - Both are optional: [code]...[/code] works with no language or filename
+
+  3. Terminal Output
+
+  [terminal]
+  $ docker ps
+  CONTAINER ID   IMAGE     STATUS
+  a1b2c3d4e5f6   nginx     Up 2 hours
+  [/terminal]
+
+  - Syntax: [terminal]...[/terminal]
+  - Used for showing expected command output, logs, or interactive terminal sessions
+  - Rendered with a terminal-style dark background
+
+  4. Callout
+
+  [callout:info]
+  Docker must be running before you proceed to the next step.
+  [/callout]
+
+  [callout:warning]
+  This will delete all existing containers. Back up your data first.
+  [/callout]
+
+  [callout:danger]
+  Never run this command on a production server without testing first.
+  [/callout]
+
+  [callout:tip]
+  You can add this to your .bashrc to make it permanent.
+  [/callout]
+
+  - Syntax: [callout:variant]...[/callout]
+  - Variants: info, warning, danger, tip
+  - Content inside supports Markdown
+
+  5. Image
+
+  [image: https://example.com/screenshot.png | Screenshot of the dashboard]
+
+  - Syntax: [image: url | caption]
+  - url — image source URL (required)
+  - | caption — optional, used as both alt text and caption
+
+  6. Video
+
+  [video: https://example.com/demo.mp4]
+
+  - Syntax: [video: url]
+  - Accepts direct video URLs (MP4, WebM)
+
+  7. URL Embed
+
+  [url: https://github.com/example/repo]
+
+  - Syntax: [url: href]
+  - Renders as a linkcard/embed
+
+--
+  Notes for Guide Authors
+
+  - Every block tag ([code], [terminal], [callout]) must have a matching closing tag ([/code],
+[/terminal], [/callout])
+  - [image], [video], and [url] are self-closing (no closing tag needed)
+  - Standard Markdown links [text](url) work in text sections and are not confused with block tags
+  - Frontmatter fields use key: value syntax (one per line, no nesting)
+  - The parser round-trips: markup → JSON → markup without data loss