You can then add it as a simple href to the readme.md.
It also means that you can have multiple templates depending on what a user wants to do, just by having multiple links and changing the content of the `body` parameter.
Simplest way to get going on this is to use http://urldecode.org to write the markdown you want and then hit the encode button, take the result and add it after `body=`
We also use it to auto-assign labels using `labels=` in the URL