Act as a seasoned SEO content strategist with 5+ years of experience in technical SEO and visual content optimization. Craft a detailed guide on best practices for optimizing Gantt charts for SEO, ensuring they are both user-friendly and search-engine-friendly. Cover the following key areas: [1] How to use descriptive, keyword-rich alt text and file names for Gantt charts, [2] Best practices for embedding Gantt charts in a way that balances visual appeal with page load speed (e.g., lazy loading, responsive design), and [3] Strategies for contextualizing Gantt charts with supporting text (e.g., captions, headings, and surrounding content) to enhance relevance for target keywords like [TARGET_KEYWORD]. Include actionable tips for tools like [TOOL_NAME] to automate optimizations. Keep the tone professional yet accessible, targeting project managers and SEO specialists.