v1.21 - Puzzle 12 logic

v1.21:

• Puzzle 12: Now has a more logic-based solution, like it used to. (Replaced the circle and line blots with just a few small blots, to avoid misinterpretation.)
• Puzzle 11: Small tweaks to reduce difficulty. (Smaller regions of letters, moved palindrome, and a reminder for crossing.)
• (printable) Puzzle 11: Darkened highlights to help them show up when printing.
• (printable) Puzzle 6: Now squigglier. (Text paths are the one thing I can't simply copy-paste between versions.)
• (PC) Added "Software Used: Inkscape" to credits.