For whatever reason, Apple launched iOS 12's Shortcuts app without offering users any kind of centralised hub for storing and sharing the useful shortcuts they create. So, this happens: You find a neat shortcut online, you pull up Safari on your iOS device and install it via some shared iCloud link, and it sits on your device forever.
If the shortcut's developer updates it to include more functionality (or fix bugs), you'll never receive any kind of prompt letting you know about changes — not unless you rediscover the shortcut and notice something is new.
In other words, Shortcuts needs an App Store, or at least some place where users can upload, find, and update shortcuts. I doubt Apple has any plans to make this happen anytime soon, so I'm thrilled that someone else has: RoutineHub.
More importantly, if you have a shortcut you want to share with the world, RoutineHub makes it easy to add in an update module (UpdateKit), which gives you version control and your shortcut's fans a way to get the latest and greatest version of your creation.
Uploading new Shortcuts to RoutineHub (using the cleverly named "RoutinePub") takes a little work to get going, but it's worth the initial setup — especially since you'll then be able to publish shortcuts (or updates to shortcuts) directly to RoutineHub from the iOS Shortcuts app. You can also integrate UpdateKit into your own shortcuts without using RoutineHub at all, but it sure is handier to use the free hosting solution that's already been created for you.
Here's how the whole update process works, courtesy of UpdateKit creator (and RoutinePub co-creator) Mike Beasley. If you just want to see what it looks like when one of your shortcuts has a new version, skip to 1:15 in the video: