Please, merge my PowerShell examples for all chapters (#106)

* PowerShell 01_introduction_to_algorithms example

* PowerShell 02_selection_sort example

* PowerShell 03_recursion examples

* PowerShell 04_quicksort examples

* PowerShell 05_hash_tables examples

* PowerShell 06_breadth-first_search example

* PowerShell 07_dijkstras_algorithm example

* PowerShell 08_greedy_algorithms example

* Powershell 09_dynamic_programming example

01_introduction_to_algorithms/PowerShell/01_binary_search.ps1

@@ -0,0 +1,39 @@
+function Search-GRKBinary
+{
+    param ($list, $item)
+
+    # $low and $high keep track of which part of the list you'll search in.
+    $low = 0;
+    $high = $list.Length - 1;
+
+    # While you haven't narrowed it down to one element ...
+    while ($low -le $high)
+	{
+        # ... check the middle element
+        $mid = [int](($low + $high) / 2);
+        $guess = $list[$mid];
+        # Found the item.
+        if ($guess -eq $item)
+        {
+            return $mid;
+        }
+        # The guess was too high.
+        if ($guess -gt $item)
+        {
+            $high = $mid - 1
+        }
+        # The guess was too low
+        else
+        {
+            $low = $mid + 1
+        }
+              
+    }
+
+    # Item doesn't exist
+    return $null;
+}
+
+$mylist = (1, 3, 5, 7, 9);
+Search-GRKBinary $mylist 3 # => 1
+Search-GRKBinary $mylist -1 # => $null