Update SliceTricks.md

Added one more delete trick

Author: IgorBuchelnikov

SliceTricks.md

@@ -40,6 +40,9 @@ a = append(a[:i], a[j:]...)
 a = append(a[:i], a[i+1:]...)
 // or
 a = a[:i+copy(a[i:], a[i+1:])]
+// or
+copy(a[i:], a[i+1:])
+a = a[:len(a)-1]
 ```
 
 #### Delete without preserving order