README.md in sigh-0.5.1 vs README.md in sigh-0.5.2

@@ -163,10 +163,10 @@
 
 ## Environment Variables
 In case you prefer environment variables:
 
 - `SIGH_USERNAME`
-- `SIGH_APP_IDENTIFIER`
+- `SIGH_APP_IDENTIFIER` (The App's Bundle ID , e.g. `com.yourteam.awesomeapp`)
 - `SIGH_TEAM_ID` (The Team ID, e.g. `Q2CBPK58CA`)
 - `SIGH_PROVISIONING_PROFILE_NAME` (set a custom name for the name of the generated file)
 
 Choose signing certificate to use: