Add a few more event triggers, to be triggered only once

events_triggered.md

@@ -1,7 +1,20 @@
 # Events
 This is a list of events that gochan may trigger at some point, that can be used in the plugin system.
 
+- **db-connected**
+	- Triggered after gochan successfully connects to the database but before it is checked and initialized (db version checking, provisisioning, etc)
+
+- **db-initialized**
+	- Triggered after the database is successfully initialized (db version checking, provisioning, etc)
+
 - **incoming-upload**
 	- Triggered by the `gcsql` package when an upload is attached to a post. It is triggered before the upload is entered in the database
+
+- **shutdown**
+	- Triggered when gochan is about to shut down, in `main()` as a deferred call
+
+- **startup**
+	- Triggered when gochan first starts after its plugin system is initialized. This is (or at least should be) only triggered once.
+
 - **upload-saved**
 	- Triggered by the `posting` package when an upload is saved to the disk but before thumbnails are generated.