This directory contains miscellaneous documentation such as the TypeScript language specification and logo. If you are looking for more introductory material, you might want to take a look at the TypeScript Handbook.
The specification is first authored as a Microsoft Word (docx) file and then generated into Markdown and PDF formats. Due to the binary format of docx files, and the merging difficulties that may come with it, it is preferred that any suggestions or problems found in the spec should be filed as issues rather than sent as pull requests.