1.2.0
Update the figures and cover images (#1020)
Figures revision and bug fixes (#1041)
Bug fixes and improvements (#1348)
feat: add ruby code blocks - chapter tree (#1293)
Update avl_tree.md (#1524)
Use underline format for the technical terms (#1213)
Update binary_tree.md (#1454)
Bug fixes and improvements (#1205)
Update the format of the Q&As (#1031)