* Update avl_tree.md
* Remove the empty space
* Simplify the heading of the paperbook chapter
* Update hash_map_open_addressing.go to the latest version
* Improvements
* Use Roboto mono as the font of the footers
* Bug fixes
* Add the introduction to the paper book.
* Add the 'new' label to the toc
* Turn off the autoplay
* Polish the intro to paperbook
* Update suggestions.md
* Add announcement of the paper book release
* Fix size of svg
* Update contrib rocks image
* Optimize HTML of the landing page
* Fix the line breaks