chore: Plugin registration (#6623)

* first pass

* test

* test

* priority

* Reduce boilerplate further

* Update server/utils/PluginManager.ts

Co-authored-by: Apoorv Mishra <apoorvmishra101092@gmail.com>

* fix: matchesNode error in destroyed editor transaction

* fix: Individual imported files do not display source correctly in 'Insights'

* chore: Add sleep before Slack notification

* docs

* fix: Error logged about missing plugin.json

* Remove email template glob

---------

Co-authored-by: Apoorv Mishra <apoorvmishra101092@gmail.com>

plugins/slack/plugin.json

@@ -1,5 +1,6 @@
 {
+  "id": "slack",
   "name": "Slack",
-  "description": "Adds a Slack authentication provider, support for the /outline slash command, and link unfurling.",
-  "requiredEnvVars": ["SLACK_CLIENT_ID", "SLACK_CLIENT_SECRET"]
+  "priority": 40,
+  "description": "Adds a Slack authentication provider, support for the /outline slash command, and link unfurling."
 }