[feature] Instance rules (#2125)

* init instance rules database model, admin api

* expose instance rules in public instance api

* public /api/v1/instance/rules route

* GET ruleById

* createRule route

* createRule auth check

* updateRule

* deleteRule

* list rules on about page

* ruleGet auth

* add about page ids for anchors

* process and store adding violated rules to reports

* admin api models for instance rules

* instance rule edit frontend

* change rule inputs to textareas

* database fixes after rebase (#2124)

* remove unused imports

* fix db migration column name

* fix tests

* fix more tests

* fix postgres error with wrongly used Ident

* add some tests, fiddle with rule model a bit, fix postgres migration

* swagger docs

---------

Co-authored-by: tsmethurst <tobi.smethurst@protonmail.com>

internal/api/model/instancev2.go

@@ -62,9 +62,8 @@ type InstanceV2 struct {
 	Registrations InstanceV2Registrations `json:"registrations"`
 	//  Hints related to contacting a representative of the instance.
 	Contact InstanceV2Contact `json:"contact"`
-	// An itemized list of rules for this website.
-	// Currently not implemented (will always be empty array).
-	Rules []interface{} `json:"rules"`
+	// An itemized list of rules for this instance.
+	Rules []InstanceRule `json:"rules"`
 }
 
 // Usage data for this instance.