Remove alt from markdown image

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

README.md

@@ -18,7 +18,7 @@ It benefits directly from the experience accumulated over several years
 of large-scale operation and support of hundreds of thousands of
 applications and databases.
 
-![Docker L](docs/static_files/docker-logo-compressed.png "Docker")
+![](docs/static_files/docker-logo-compressed.png "Docker")
 
 ## Security Disclosure