Add database design posts and project documentation

- Add CLAUDE.md with project setup and architecture guidelines
- Add .markdownlint.json configuration
- Add data-modeling-normalization and enterprise-database-design-patterns posts
- Remove data-modelling-process.md

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

Author: Abhigyan Prakash

.markdownlint.json

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+{
+    "MD024": false,
+    "MD013": false
+}

CLAUDE.md

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+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+Personal tech notes site built with Hugo and the PaperMod theme. Posts are written in Markdown with TOML frontmatter.
+
+## Commands
+
+```bash
+# Development server (includes drafts)
+hugo server -D
+
+# Production build
+hugo --minify
+
+# Create new post
+hugo new posts/my-post-title.md
+```
+
+## Architecture
+
+- **Theme**: PaperMod installed as git submodule in `themes/hugo-PaperMod`
+- **Content**: All posts go in `content/posts/` as Markdown files
+- **Custom layouts**: `layouts/` contains overrides for PaperMod
+  - Mermaid diagram support via `_default/_markup/render-codeblock-mermaid.html` and `partials/extend_footer.html`
+- **Deployment**: GitHub Actions workflow deploys to GitHub Pages on push to `main`
+
+## Post Frontmatter
+
+Posts use TOML frontmatter (`+++` delimiters). Key fields:
+- `title`, `date`, `draft`, `tags`, `summary`
+- `mermaid = true` to enable Mermaid diagrams in a post
+- `ShowToc = false` to hide table of contents
+
+## Adding Images to Posts
+
+Use page bundles: create a folder with post name containing `index.md` and images:
+```
+content/posts/my-post/
+├── index.md
+└── diagram.png
+```