This is especially true if you've written any tunes. But it would also be valuable if you would document your crowd's versions of old tunes. There is already enough abc online that the scholarly types are starting to talk about it as a resource. You can help them by documenting the popular versions of tunes in your area. And you'll end up with an online tune book that you can give to newcomers and novices who want to join in.
Try to include all the information that you know about each tune in the abc header lines. For tunes that you wrote, include your email or web address and a copyright notice. One N: line will do. Then people will know how to contact you about the tune.
My site is only as valuable as the collection of online abc tunes. So do your part ...