update readme

README.md

@@ -8,6 +8,8 @@
 
 Reverse-engineered Bluetooth protocol for the Tandem t:slim X2.
 
+> :warning: **This project is still in heavy testing and development. For safety reasons, please do NOT use on anything but a backup pump or one not connected to active insulin delivery.**
+
 Currently functions as a basic Android application which pairs to the pump
 and allows sending read-only message requests and receiving responses about
 the pump's status and history. An Android library is exported which can be used
@@ -105,4 +107,4 @@ dependencies {
 A `pumpx2-messages-all.jar` is also available on Github Actions as a fat JAR which contains all dependencies.
 This may or may not work with your project depending on if there are any conflicting dependencies.
 
-To utilize the command-line message-parsing tool, execute the `pumpx2-cliparser-all.jar` file using `java -jar`.
+To utilize the command-line message-parsing tool, execute the `pumpx2-cliparser-all.jar` file using `java -jar`.