Typography fixes (#6260)

Headings line height and weight updates

antonia/theme.json

@@ -13,8 +13,8 @@
 				"typography": {
                     			"fontFamily": "var:preset|font-family|dm-sans",
 					"fontStyle": "normal",
-					"lineHeight": "1.4",
-					"fontWeight": "300"
+					"lineHeight": "1.3",
+					"fontWeight": "700"
 				}
 			},
 			"core/post-title": {