This is a rather minor nitpick, but I think the documentation and TauCharts website as a whole could use some editing by a native English speaker. That said, the content and goals for the project really are quite cool! I'm looking forward to where TauCharts can go in the future.
If your goal is to express ideas and get someone to contribute/download/convert, I don't think that's a minor nitpick at all. It was pretty painful to read certain parts.
As well documentation for taucharts is open sourced: https://github.com/TargetProcess/taucharts-docs. You can help a project.. just send pull requests with corrected grammar.