bumped version to 0.20. 

bumped version to 0.19. 

bumped version to 0.18. 

doc: markdown formatting fixes. 

bumped version to 0.16. 

bumped version to 0.15. 

bumped version to 0.14. 

bumped version to 0.13. 

bumped version to 0.12. 

bumped version to 0.11.