exodrone adventures are no longer database based (#78636)

## About The Pull Request

you now put the jsons into the folder at strings/exoadventures
no adventures have been lost i think
also deletes the example_adventures folder since theyre just duplicates
of the adventures in the other folder now

## Why It's Good For The Game

having it database based meant you had to ping someone with database
access to add it which isnt exactly optimal for contributions

## Changelog
🆑
code: exploration drone adventures are now file-based and not
database-based
/🆑

---------

Co-authored-by: san7890 <the@san7890.com>

SQL/tgstation_schema.sql

@@ -637,19 +637,6 @@ CREATE TABLE `discord_links` (
 	PRIMARY KEY (`id`)
 ) ENGINE=InnoDB;
 
---
--- Table structure for table `text_adventures`
---
-DROP TABLE IF EXISTS `text_adventures`;
-CREATE TABLE `text_adventures` (
-	`id` int(11) NOT NULL AUTO_INCREMENT,
-	`adventure_data` LONGTEXT NOT NULL,
-	`uploader` VARCHAR(32) NOT NULL,
-	`timestamp` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
-	`approved` TINYINT(1) NOT NULL DEFAULT FALSE,
-	PRIMARY KEY (`id`)
-) ENGINE=InnoDB;
-
 --
 -- Table structure for table `admin_connections`
 --