Update README with demo gif and description of current project status

Author: ottok

README.md

@@ -1,17 +1,24 @@
 # db-ping
 
-MariaDB/MySQL compatible database connection and capability checker
+**MariaDB/MySQL compatible database connection and capability checker**
 
-This tool helps to quickly identify database connectivity issues such as:
+Is your database connection unstable? Do you want to know the SLA of your
+database connection over a longer period, or just quickly measure how long of a
+downtime a database restart or some other operation caused? When the database
+isn't serving queries, do you want to know exacly why?
+
+This tool helps to measure and identify database connectivity issues such as:
+- Downtime duration and SLA
 - DNS propagation delay, hostname not matching active database server
 - TCP/IP routing issues, server not reachable
 - TLS certificate issues
 - Authentication errors
 - Server load issues: too many connections, too many queries or too much load
 - Server health issues: disk write operations stalled or other I/O delay
 
-## Under development
+![Demo of db-ping](db-ping.gif)
 
-This tool is in very early stages of development and not intended for general use yet.
+## Under development
 
-The code has a lot of commented-out incomplete sections, and it hasn't been refactored to clean up boilerplate code etc. But it runs! :)
+This tool is in very early stages of development and not intended for general
+use yet, but it does run and can be tested.