Update contribution guidelines

Created a template for more consistent instruction format
Updated the readme to reflect a more structured process for box creation
DO NOT MERGE until box docs have been updated and truffle boxes have been cleaned up

README.md

@@ -1,10 +1,23 @@
 # Blueprint Truffle Box
 
-This box comes with everything you need to create your own Truffle Box.
+This box comes with everything you need to get started on your own Truffle Box.
 
 ## Getting Started
 
-After adding your libraries and code:
+First, fork this repository to create your own repository and make edits. Then, start adding your libraries and code!
+See the [Create your own Truffle Box](https://trufflesuite.com/docs/truffle/advanced/creating-a-truffle-box.html) section of our documentation on how to do so.
+
+## Truffle Site Listing
+
+In order for your box to be published, we have a few requirements to make sure it's in tip-top shape to get released.
+
+Please include detailed instructions to help the community get started using it right away! To do so:
+
+1. Fill out our [template README](./readme-template.md). Note that not everything in the template may apply, or you may need to expand it to best fit your box. See our [Optimism Box](https://github.com/truffle-box/optimism-box) for a great example!
+
+2. Rename the file to `README.md`.
+
+Please also include the images you wish to be displayed with your box. To do so:
 
 1. Delete `box-img-sm.png` and `box-img-lg.png`.
 
@@ -14,4 +27,4 @@ After adding your libraries and code:
 
 4. Customize the box configuration file (`truffle-box.json`) if necessary.
 
-See [the Truffle Box section of our documentation](https://trufflesuite.com/docs/truffle/advanced/creating-a-truffle-box.html) for more info.
+For more detailed instructions on what we look for and how to submit, see the [Truffle Site Listing](https://trufflesuite.com/docs/truffle/advanced/creating-a-truffle-box/#truffle-site-listing) section of our documentation.