fix: add alignment attribute to heading, text substitute

Author: Arukuen

src/block/heading/substitute.js

@@ -5,6 +5,7 @@ export const substitute = {
 		return {
 			content: oldAttributes.text,
 			level: oldAttributes.textTag ? Number( oldAttributes.textTag.replace( 'h', '' ) ) : 2,
+			textAlign: oldAttributes.contentAlign,
 		}
 	},
 }

src/block/text/substitute.js

@@ -4,6 +4,7 @@ export const substitute = {
 	transform: oldAttributes => {
 		return {
 			content: oldAttributes.text,
+			align: oldAttributes.contentAlign,
 		}
 	},
 }