CSS
In Customize -> Additional CSS, add the following code:
.clearflow {
clear: both;
}
figure.alignleft {
margin-right: 1rem;
}
Blocks
Insert blocks in the following order:
Image
Paragraph
...
Paragraph
Image
Paragraph
...
Paragraph
Select Image block, and on its toolbar, select Align left icon. In Advanced -> Additional CSS Class section, add clearflow
class.
Repeat this for every Image block.