extract company profiles intro top/bottom content into markdown files. Make minor text edits.
Implement TextRender.safe_markdown, and use it to render user-entered input on the edit-company-profile form. Bump redcarpet to version 3.1.1.
Merge pull request #44 from code-dot-org/hoc-ee-markdown

Extract HoC EE markdown into separate files and touch up content.