0.29.0.gfm.7

Changes since last release (0.29.0.gfm.6...0.29.0.gfm.7):

• Fixed CVE-2023-22486, a polynomial time complexity issue in cmark-gfm which may lead to unbounded resource exhaustion and subsequent denial of service.
• Fixed CVE-2023-22485, in which a crafted markdown document could trigger an out-of-bounds read in the validate_protocol function.
• Fixed CVE-2023-22484, a polynomial time complexity issue in cmark-gfm which may lead to unbounded resource exhaustion and subsequent denial of service.
• Fixed CVE-2023-22483, several polynomial time complexity issues in cmark-gfm which may lead to unbounded resource exhaustion and subsequent denial of service.
• We removed an unneeded .DS_Store file (#291)
• We added a test for domains with underscores and fix roundtrip behavior (#292)
• We now use an up-to-date clang-format (#294)
• We made a variety of implicit integer truncations explicit by moving to size_t as our standard size integer type (#302)
• We introduced a new flag mechanism that is used in cmark node state management, which requires clients call the cmark_init_standard_node_flags function at program startup (420c20a)

The security issues were reported and resolved by @kevinbackhouse and @philipturnbull of the GitHub Security Lab