Implement markdown reference renderer

[seesharprun]

This pull request migrates the reference documentation system from YAML-based files to Markdown with frontmatter, streamlining content management and rendering. It updates the data loading, parsing, and display logic to support Markdown content and frontmatter metadata, and simplifies the reference type/category handling. Additionally, it introduces improvements to the UI components and enforces better ESLint configuration for Next.js projects.

Reference Content System Migration

• Migrated reference documentation from .yml files to Markdown (.md) files with frontmatter, removing the old Reference type and YAML parsing logic. The new ReferenceArticle type uses Markdown content and frontmatter for metadata. ([[1]](https://github.com/seesharprun-documentdb-prototype/seesharprun-documentdb-prototype.github.io/pull/4/files#diff-949243a5c4723bf3adcb4da260acfa523993dab17b5af200a55d2ace232ddc4bL4-R23), [[2]](https://github.com/seesharprun-documentdb-prototype/seesharprun-documentdb-prototype.github.io/pull/4/files#diff-f024f85bc78e59f59cdf3cbcdd3c75570b827ca97b33518a8220ebe901f8c1e9L1-L32), [[3]](https://github.com/seesharprun-documentdb-prototype/seesharprun-documentdb-prototype.github.io/pull/4/files#diff-3ef7770fffc40400c3a00e84caf0df8eddb0aa92a3ecf2bdc89709daf6f5fb59L1-L99))
• Updated all reference data loading functions in referenceService.ts to parse Markdown files using gray-matter, extract metadata from frontmatter, and group references accordingly. ([[1]](https://github.com/seesharprun-documentdb-prototype/seesharprun-documentdb-prototype.github.io/pull/4/files#diff-949243a5c4723bf3adcb4da260acfa523993dab17b5af200a55d2ace232ddc4bR32-R104), [[2]](https://github.com/seesharprun-documentdb-prototype/seesharprun-documentdb-prototype.github.io/pull/4/files#diff-949243a5c4723bf3adcb4da260acfa523993dab17b5af200a55d2ace232ddc4bR118), [[3]](https://github.com/seesharprun-documentdb-prototype/seesharprun-documentdb-prototype.github.io/pull/4/files#diff-949243a5c4723bf3adcb4da260acfa523993dab17b5af200a55d2ace232ddc4bL90-R136), [[4]](https://github.com/seesharprun-documentdb-prototype/seesharprun-documentdb-prototype.github.io/pull/4/files#diff-949243a5c4723bf3adcb4da260acfa523993dab17b5af200a55d2ace232ddc4bL111-R166))

Rendering and UI Updates

• Refactored the reference page ([type]/[category]/[name]/page.tsx) to render Markdown content using a new Markdown component, and to use metadata from frontmatter for titles and descriptions. Removed all legacy YAML-driven rendering logic for syntax, parameters, examples, and related sections. ([app/docs/reference/[type]/[category]/[name]/page.tsxL1-R22](https://github.com/seesharprun-documentdb-prototype/seesharprun-documentdb-prototype.github.io/pull/4/files#diff-3f5224d135d8b78ac46db8fd5df1111eaac2960dea207c75cfbfc214cf3ed77bL1-R22), [app/docs/reference/[type]/[category]/[name]/page.tsxL25-R61](https://github.com/seesharprun-documentdb-prototype/seesharprun-documentdb-prototype.github.io/pull/4/files#diff-3f5224d135d8b78ac46db8fd5df1111eaac2960dea207c75cfbfc214cf3ed77bL25-R61))
• Updated the Breadcrumb and index navigation components to use singular/plural forms more accurately and to reflect the new data structure. ([[1]](https://github.com/seesharprun-documentdb-prototype/seesharprun-documentdb-prototype.github.io/pull/4/files#diff-6a624229fb96feb6662ee50b24d0aa471cef15681e68cae57eb1626aef4fc59bL19-R19), [[2]](https://github.com/seesharprun-documentdb-prototype/seesharprun-documentdb-prototype.github.io/pull/4/files#diff-3c59db339cff18eabfe3c53e08c876ba0fc2ab212afe60818246b1b0332ed2c2R7), [[3]](https://github.com/seesharprun-documentdb-prototype/seesharprun-documentdb-prototype.github.io/pull/4/files#diff-3c59db339cff18eabfe3c53e08c876ba0fc2ab212afe60818246b1b0332ed2c2L37-R38))

Reference Type/Category Handling

• Changed allowed reference types from singular (operator, command) to plural (operators, commands) throughout the codebase for consistency with new file organization. ([app/docs/reference/[type]/page.tsxL10-R14](https://github.com/seesharprun-documentdb-prototype/seesharprun-documentdb-prototype.github.io/pull/4/files#diff-27bf72f7401d9d94c3d1b53fab33657278f7b040166ac5f48ea67a8d90f1aebbL10-R14))

Tooling and Linting

• Added @next/eslint-plugin-next to the ESLint configuration and package.json to enforce Next.js best practices. ([[1]](https://github.com/seesharprun-documentdb-prototype/seesharprun-documentdb-prototype.github.io/pull/4/files#diff-9601a8f6c734c2001be34a2361f76946d19a39a709b5e8c624a2a5a0aade05f2R2-R12), [[2]](https://github.com/seesharprun-documentdb-prototype/seesharprun-documentdb-prototype.github.io/pull/4/files#diff-7ae45ad102eab3b6d7e7896acd08c427a9b25b346470d7bc6507b6481575d519R26))

(References: [1] [2] [3] app/docs/reference/[type]/[category]/[name]/page.tsxL1-R22, app/docs/reference/[type]/[category]/[name]/page.tsxL25-R61, [4] [5] [6] app/docs/reference/[type]/page.tsxL10-R14, [7] [8]