Docs: Move non-library dependencies to the bottom, mention tkinter [ci skip]

Author: F30

docs/installation.rst

@@ -171,11 +171,6 @@ Many of Pillow's features require external libraries:
     transparent WebP files. Versions **0.3.0** and above support
     transparency.
 
-* **tcl/tk** provides support for tkinter bitmap and photo images.
-
-* **olefile** provides support for Kodak FlashPix (FPX) and Microsoft
-  Image Composer (MIC) files.
-
 * **openjpeg** provides JPEG 2000 functionality.
 
   * Pillow has been tested with openjpeg **2.0.0**, **2.1.0**, **2.3.1**,
@@ -210,6 +205,12 @@ Many of Pillow's features require external libraries:
 
 * **libxcb** provides X11 screengrab support.
 
+* **tcl/tk** and the **tkinter** Python bindings provide support for tkinter
+  bitmap and photo images.
+
+* **olefile** provides support for Kodak FlashPix (FPX) and Microsoft
+  Image Composer (MIC) files.
+
 .. tab:: Linux
 
     If you didn't build Python from source, make sure you have Python's