This is to show that you’ve been growing.
To show yourself that you’re working towards reaching that level you dream to attain.
Documentation can be as little as you writing down your daily activities or as large as you celebrating your little and major wins either with your self or with friends.
In another way, documentation can be described as you writing down experiences from a journey.
You can document with a diary or make a video, podcast or probably share a blog post about an experience.
Just put something down.
And observe yourself grow.