feat: change article load logic

- change highlighter prism to shiki
- separate logic into several files

src/lib/server/database/get_connection.ts

@@ -14,6 +14,6 @@ const pool = new Pool({ connectionString });
 
 export const getConnection = () => pool;
 
-import init from '$lib/server/database/init_db';
+import init_db from '$lib/server/database/init';
 import PG from '$lib/server/database';
-await init(await PG(pool));
+await init_db(await PG(pool));