Allison Tharp has a script to create SSMS snippets:
One issue with SSMS’s Snippet Manager is that the code has to be stored in a .Snippet file in a specific location on your local machine. The .Snippet files are in XML format, which is a little inconvenient since we don’t write SQL in XML format. This means that in order to add a new snippet, you need to create a new .Snippet file in the correct format, add the SQL to it, and save it in the right location. After that, you must import the file through SSMS.
I have had ideas for snippets, but it is enough of an inconvenience to sometimes prevent me from going through the motions of making an actual snippet file. I wanted to write some kind of code that would allow me to save a SQL file into a specific folder and let an automated program convert it into the Snippet format. I’ve also been wanting to learn PowerShell, so I thought this would be a good opportunity!
The next step would be turning that into a cmdlet.