v3.21.2

Bug fixes

• Fix media_type undefined error when adding locator map image to EPUB footnote(ef5092f)
• Fix Fandom cache folder not exists error(50c3b5c)
• Fix substring not found error for some MOBI , AZW3 and EPUB books(41cae53)

Other changes

• Replace full name in Chinese and Japanese books that have interpunct(f966874)
• Only extent X-Ray length when the next character is punctuation(dd2f53d)
• Update dependencies