A duplicate orderBy usage example removed (#47)

Author: sadedil

docs/array.md

@@ -436,7 +436,6 @@ const values = [
 {{ values | orderBy: '+a' }} <!-- Will order the values by a (asc)-->
 {{ values | orderBy: ['a'] }} <!-- Will order the values by a (asc)-->
 {{ values | orderBy: '-a' }} <!-- Will order the values by a (desc)-->
-{{ values | orderBy: ['-a', 'b'] }} <!-- Will order the values by a (desc)-->
 {{ values | orderBy: ['-a', 'b'] }} <!-- Will order the values by a (desc) and b (asc) -->
 {{ values | orderBy: ['-a', '+b'] }} <!-- Will order the values by a (desc) and b (asc) -->
 {{ values | orderBy: ['-a', '-b'] }} <!-- Will order the values by a (desc) and b (desc) -->
@@ -685,4 +684,4 @@ import { FlattenPipe } from 'angular-pipes/src/array/flatten.pipe';
 {{ [[1, 2, 3, 4]] | flatten }} <!-- [1, 2, 3, 4] -->
 {{ [[1, 2, 3, [4]] | flatten }} <!-- [1, 2, 3, [4]] -->
 {{ [[1, 2, 3, [4]] | deep | flatten }} <!-- [1, 2, 3, 4] -->
-```
+```