In case you want to show the collection description at the bottom of the page. You should perform the following steps.
Note: You should be able to edit the theme source code at Theme actions -> Edit code. Or hire a Shopify Expert to complete this task for you.
1) Create a backup copy of your theme at Theme actions -> Duplicate. You may quickly restore the working theme in case something goes wrong.
2) Go to Theme actions -> Edit code.
3) Open the snippets/collection-head.liquid file
4) Find the following code
<div class="rte fs{{ description_class }}"> {{ collection.description }} </div>
5) Cut it from the snippets/collection-head.liquid file & paste at the snippets/collection-page.liquid file. After the collection-body section
You should get
a) Updated snippets/collection-head.liquid file
b) Updated snippets/collection-page.liquid file
c) Collection description after the product list.
d) You may add additional margin with mt-100 class.
mt - short for margin top
100 - distance in pixels, you may use other number with set of 10 pixels.
It looks better now.
Done.
Thank you for using the Shella theme.