Version 1.2.1

• Used bumpversion for our version control system.
• Applied block accessories with \drawcage command.
• Added more examples into demo document.
• Changed background color to onyx(缟 in Chinese) and building color to snow white.
• Changed theorem style to numbered.
• Set footnote mark color to emerald green(松花色 in Chinese).
• Changed itemize environment's appearence with \drawpetal.
• Adjusted progress bar's line width to 0.3pt.
• Minor bug and typo fixes.