agentmap@0.5.0

• Add README.md support: include README files in the map with their content as description
• README files appear first in each folder's listing
• Case-insensitive matching for readme, README, readme.md, README.md
• Use marked lexer to parse markdown AST and extract plain text
• Skip images, HTML comments, and badges from markdown content
• Truncate descriptions to 25 lines with ... and N more lines indicator
• Graceful fallback to raw content if markdown parsing fails