#50 - updated TOC header

- signed-off-by: trimstray <trimstray@gmail.com>

README.md

@@ -61,7 +61,7 @@ Before add pull request please see **[this](https://github.com/trimstray/the-boo
 - [ ] Add one-liners for collection tools (eg. CLI Tools)
 - [ ] Generate book pdf format
 
-## :anger:  Table Of Content
+## :anger:  Table of Contents
 
 Only main chapters: