+ Badges introduction to database schemas

+ Adding some default empty list values where applicable
neighbors now has a default value of '[]' to enforce the "empty list" constraint on that field

json-api/migrations/2021-05-04-200859_neighbors/up.sql

@@ -6,5 +6,5 @@ CREATE TABLE IF NOT EXISTS `neighbors`(
 	`wsurl` VARCHAR(512),
 	`name` VARCHAR(512) NOT NULL,
 	`description` VARCHAR(1024),
-	`tags` VARCHAR(1024)
+	`tags` VARCHAR(1024) DEFAULT '[]'
 );