Fix some markdown issues (#32)

Author: username1001

Instructions/Labs/03a-joins.md

@@ -81,7 +81,7 @@ An outer join is used to retrieve all rows from one table, and any corresponding
 
 2. Run the query and note that the results contain data for every customer. If a customer has placed an order, the order number is shown. Customers who have registered but not placed an order are shown with a *NULL* order number.
 
-    Note the use of the **LEFT** keyword. This identifies which of the tables in the join is the *outer* table (the one from which all rows should be preserved). In this case, the join is between the **Customer** and **SalesOrderHeader** tables, so a **LEFT** join designates **Customer** as the outer table. Had a **RIGHT** join been used, the query would have returned all records from the **SalesOrderHeader** table and only matching data from the **Customer**table (in other words, all orders including those for which there was no matching customer record). You can also use a **FULL** outer join to preserve unmatched rows from *both* sides of the join (all customers, including those who haven't placed an order; and all orders, including those with no matching customer), though in practice this is used less frequently.
+    Note the use of the **LEFT** keyword. This identifies which of the tables in the join is the *outer* table (the one from which all rows should be preserved). In this case, the join is between the **Customer** and **SalesOrderHeader** tables, so a **LEFT** join designates **Customer** as the outer table. Had a **RIGHT** join been used, the query would have returned all records from the **SalesOrderHeader** table and only matching data from the **Customer** table (in other words, all orders including those for which there was no matching customer record). You can also use a **FULL** outer join to preserve unmatched rows from *both* sides of the join (all customers, including those who haven't placed an order; and all orders, including those with no matching customer), though in practice this is used less frequently.
 
 3. Modify the query to remove the **OUTER** keyword, as shown here: