chore: add projectops docs

[mnkiefer]

• Added ProjectOps documentation with example that demonstrates how to automate GitHub Projects board management using agentic workflows, including campaign tracking, content-based routing, and dynamic field assignment.
• Added a Campaigns guide to highlight campaign workflow patterns.
• Updated the issue and PR event workflow documentation to reference the new ProjectOps example, making it easier for users to discover project automation patterns.

[Copilot]

Pull Request Overview

This PR adds comprehensive ProjectOps documentation and refactors the Campaigns guide to better differentiate between campaign orchestration and project board management patterns. The changes improve discoverability and clarity for users implementing GitHub Projects automation with AI workflows.

Key changes:

• Refactored campaigns.md to focus on multi-issue coordination patterns with clearer, more concise explanations
• Added new projectops.md documentation covering GitHub Projects board automation patterns
• Updated navigation to include ProjectOps in examples section and Campaigns in guides section

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
docs/src/content/docs/guides/campaigns.md	Streamlined campaign documentation focusing on orchestration patterns, removing verbose examples and redundant explanations
docs/src/content/docs/examples/issue-pr-events/projectops.md	New comprehensive guide for GitHub Projects automation including common patterns, best practices, and security considerations
docs/src/content/docs/examples/issue-pr-events.md	Added ProjectOps link to issue/PR events examples index
docs/astro.config.mjs	Updated navigation to include Campaigns in guides and ProjectOps in examples (alphabetically ordered)

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