Add handling to ensure user initializes the database

Author: theFestest

link_stacklog/database.py

@@ -17,11 +17,14 @@ def user_dir():
     path.mkdir(exist_ok=True, parents=True)
     return path
 
-def get_database() -> sqlite_utils.Database:
+def get_database(init=False) -> sqlite_utils.Database:
+    if not init and not (user_dir() / DATABASE_FILE).exists():
+        click.echo("Database not found. Run 'link-stacklog init' first.")
+        raise click.Abort()
     return sqlite_utils.Database(user_dir() / DATABASE_FILE)
 
 def init_db():
-    db = get_database()
+    db = get_database(init=True)
 
     db["links"].create({
         "id": int,