Don't enable --hardbreaks option in cmark

Discussion here: https://tild.es/ajm

Hard line breaks is unusual for Markdown, which normally follows HTML's
behavior with line break, and it isn't something that users familiar
with Markdown would expect.

tildes/tildes/lib/cmark.py

@@ -7,11 +7,10 @@ from ctypes import CDLL, c_char_p, c_int, c_size_t, c_void_p
 CMARK_DLL = CDLL("/usr/local/lib/libcmark-gfm.so")
 CMARK_EXT_DLL = CDLL("/usr/local/lib/libcmark-gfm-extensions.so")
 
-# Enable the --hardbreaks and --unsafe options for cmark
-# Can we import these somehow? They're defined in cmark.h as:
-# CMARK_OPT_HARDBREAKS (1 << 2)
+# Enable the --unsafe option for cmark
+# Can we import this somehow? It's defined in cmark.h as:
 # CMARK_OPT_UNSAFE (1 << 17)
-CMARK_OPTS = (1 << 2) | (1 << 17)
+CMARK_OPTS = (1 << 17)
 
 CMARK_EXTENSIONS = (b"autolink", b"strikethrough", b"table")