added brief screen demo

README.markdown

@@ -2,7 +2,13 @@
 
 > Uncover usage problems in your writing
 
-## Features of this plugin
+<br/>
+
+- - -
+![demo](screenshots/demo.gif)
+- - -
+
+## Features of the _wordy_ plugin
 
 * Pure Vimscript; no external services or libraries needed
 * Uses Vim’s native spell-check engine

screenshots/demo.txt

@@ -0,0 +1,7 @@
+
+Captured with Quicktime.
+
+Processed with:
+
+$ ffmpeg -i wordy.mov -s 700x284 -pix_fmt rgb24 -vf "lutyuv=y=val*1.3" -r 10 -f gif - | \
+  gifsicle --optimize=3 --delay=6 --crop 0,0+700x283 > ~/Desktop/out.gif