Remove override for markdown-it 13

[eatyourgreens]

markdown-api/package.json

Lines 20 to 22 in 9248ae4

	"overrides": {
	"markdown-it": "~13.0.1"
	}

The override here is a workaround to avoid installing markdown-it v8, packaged with older versions of markdownz. Now that markdownz has been upgraded to v14, this override should be removed when markdownz is upgraded.