Add movie to ReadMe

Author: briochemc

README.md

@@ -1,2 +1,33 @@
 # cmap_picker
+
 Pick a colormap from the colorbar in an image
+
+Requires the Image Processing Toolbox!
+
+## Usage
+
+https://user-images.githubusercontent.com/4486578/162355888-9562e3ff-7cd8-4d4c-ba3c-0f1adeb351af.mov
+
+1. Find an image with a colorbar you want (e.g., take a screenshot)
+
+2. Call `cmap = cmap_picker(impath)`
+   This will open a figure window with your image in it.
+
+3. Draw a rectancgle with your mouse (click-and-drag)
+   A colormap will be built by averaging over the colorbar's "width"
+   (depending on the orientation of your rectangle).
+   A colorbar will also be added next to the figure to show you the colormap
+   you just made.
+
+## Example:
+
+Try this command and select whichever colorbar you want!
+
+```matlab
+cmap = cmap_picker('https://matplotlib.org/stable/_images/sphx_glr_colormaps_001_2_0x.png');
+```
+
+and select the colormap of your choice, which will be saved in the variable `cmap` above. You can then save it or use it as you would anyother colormap!
+
+
+