Fix code block typos in docs (#341)

Author: lgrosz

doc/pgtap.mmd

@@ -3616,7 +3616,7 @@ specified index does *not* exist.
     SELECT has_trigger( :schema, :table, :trigger, :description );
     SELECT has_trigger( :schema, :table, :trigger );
     SELECT has_trigger( :table, :trigger, :description );
-    SELECT has_trigger( :table, :trigger )` ###
+    SELECT has_trigger( :table, :trigger );
 
 **Parameters**
 
@@ -3641,7 +3641,7 @@ associated must be visible in the search path.
     SELECT hasnt_trigger( :schema, :table, :trigger, :description );
     SELECT hasnt_trigger( :schema, :table, :trigger );
     SELECT hasnt_trigger( :table, :trigger, :description );
-    SELECT hasnt_trigger( :table, :trigger )` ###
+    SELECT hasnt_trigger( :table, :trigger );
 
 **Parameters**
 
@@ -3665,7 +3665,7 @@ specified trigger does *not* exist.
     SELECT has_rule( :schema, :table, :rule, :description );
     SELECT has_rule( :schema, :table, :rule );
     SELECT has_rule( :table, :rule, :description );
-    SELECT has_rule( :table, :rule )` ###
+    SELECT has_rule( :table, :rule );
 
 **Parameters**
 
@@ -3690,7 +3690,7 @@ associated must be visible in the search path.
     SELECT hasnt_rule( :schema, :table, :rule, :description );
     SELECT hasnt_rule( :schema, :table, :rule );
     SELECT hasnt_rule( :table, :rule, :description );
-    SELECT hasnt_rule( :table, :rule )` ###
+    SELECT hasnt_rule( :table, :rule );
 
 **Parameters**