We currently support any files with “README” in the name (case doesn't matter) that end in the following extensions:
•Plain text: .txt
•Markdown: .md, .mkd, .mkdn, .mdown, .markdown
•ReST: .rst, .rest, .rst.txt, .rest.txt
Any other text README files are displayed as plain text, just like a README.txt file. Binary (PDF, Word documents) and HTML files are not displayed, though a link to download them is provided.