Extensibility improvements

Update 0.6.3 - Extensibility improvements

Hey all! Just a small update to Blog to improve its extensibility.

Changelog:

• feat(extensibility): allow extensions to modify more JS components, and model attributes (#147)

To update, run:

composer update v17development/flarum-blog

If you run into any issues, please make sure to create an issue here: https://github.com/v17development/flarum-blog/issues