Update 06-join.md

Fix typo and missing space in  the following 2 lines: 

1- Use the JOIN operator to look up each Pan-STARRS obj_id for the stars we are interested in in thepanstarrs1_best_neighbour table using the source_ids that we have already identified.

2- Use the JOIN operator again to look up the Pan-STARRS photometry for these stars in the panstarrs1_original_valid table using theobj_ids we just identified.

Author: ShebMichel

episodes/06-join.md

@@ -171,11 +171,11 @@ in the Pan-STARRS catalog.
 To do that we will:
 
 1. Use the `JOIN` operator to look up each Pan-STARRS `obj_id` for the stars
-  we are interested in in the` panstarrs1_best_neighbour` table using the `source_id`s
+  we are interested in the `panstarrs1_best_neighbour` table using the `source_ids`
   that we have already identified.
 
 2. Use the `JOIN` operator again to look up the Pan-STARRS photometry for these stars
-  in the `panstarrs1_original_valid` table using the` obj_ids` we just identified.
+  in the `panstarrs1_original_valid` table using the `obj_ids` we just identified.
 
 Before we get to the `JOIN` operation, we will explore these tables.