We understand the importance of telling a story in your post and know that many photographers like to build their post by editing each image individually and then adding them to the post one by one, for these people we suggest enabling Auto Add New Images:
Make sure the Gallery is open
Click the Filter button at the bottom of the gallery and select Auto Add New Images.
Now when you export a new photo from Lightroom or another photo editor it will automatically be inserted at the bottom of your post.
Please note, if you are creating a new post, when you import the source folder all images in that folder will also add into the blog layout automatically.