Add heart box design

[amychurchwell]

Hi there! This is a box design I created from some text art I found on https://cutekaomoji.com a few years back. I've been using it in my .zshrc file locally and thought it might be a worthy contribution.

# ┌────────────── ∘°∘♡∘°∘ ──────────────┐
#              File: .zshrc
#
#   Used for setting interactive shell 
#   configuration and executing commands
#   for all users, will be read when
#   starting as an interactive shell.
#
# └────────────── °∘∘♡∘∘° ──────────────┘

Unfortunately, I struggled building this project and have not been able to test the design. I'm on MacOS and tried to use homebrew to install the dependencies on https://boxes.thomasjensen.com/build.html#unix, but continue to run into make problems that I can't really make sense of 🧐 ...

| For compilation info please refer to the boxes compilation FAQ
| at https://boxes.thomasjensen.com/faq.html#q5
/Applications/Xcode.app/Contents/Developer/usr/bin/make -C src BOXES_PLATFORM=unix LEX=flex YACC=bison build
echo parser.o lex.yy.o cmdline.o discovery.o generate.o input.o list.o parsecode.o parsing.o query.o regulex.o remove.o shape.o tools.o unicode.o > ../out/modules.txt
/Applications/Xcode.app/Contents/Developer/usr/bin/make -C ../out -f ../src/Makefile BOXES_PLATFORM=unix ALL_OBJ="parser.o lex.yy.o boxes.o cmdline.o discovery.o generate.o input.o list.o parsecode.o parsing.o query.o regulex.o remove.o shape.o tools.o unicode.o" STRIP=true \
	    CFLAGS_ADDTL="-O " flags_unix boxes
echo parser.o lex.yy.o cmdline.o discovery.o generate.o input.o list.o parsecode.o parsing.o query.o regulex.o remove.o shape.o tools.o unicode.o > ../out/modules.txt
bison --warnings=all --verbose --defines=parser.h --output=parser.c ../src/parser.y
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/bison: unrecognized option `--warnings=all'
Try `/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/bison --help' for more information.
make[2]: *** [parser.c] Error 1
make[1]: *** [build] Error 2
make: *** [build] Error 2

So hopefully this design is coded correctly, apologies if not.

[tsjensen]

Thank you for sharing this cute box design!

Unfortunately, since it's not ASCII, we can't use it at the moment, until #72 is implemented. But we'll keep it around so we can add it once MBCS designs are supported.

If you have trouble building boxes, consider opening a separate issue for that. Mac is one of the frequently used platforms, so it should be fairly straightforward to get a working copy of boxes on your Mac. (Then again, I don't have access to a Mac myself, but maybe we can get someone else to help you.)