fix scripts/linkify-changelog to not blast fenced code blocks
fix scripts/linkify-changelog to not blast fenced code blocks

Signed-off-by: Christopher Hiller <cba4593484830aa757cb097d8d9f0ea9b692b304@boneskull.com>

mochajs/mocha,adamgruber/mocha,mochajs/mocha,adamgruber/mocha,adamgruber/mocha,mochajs/mocha