updated usage details

README.md

@@ -15,7 +15,7 @@ export CLICKUP_REDIRECT_PORT=9999  (optional, CLI will default to port 4321, jus
 ### Authentication
 1. The first time the app is used, it will open a browser and ask the user to log in to ClickUp to give the client app permission to exchange data with the corresponding workspace. The client may only be used with one workspace at a time.
 
-### Get Tasks  
+### Get Task  
 
 1. From the Clickup app, copy the TaskID for the task you'd like to retrieve (e.g. `#123456`).  
 1. Provide the task ID as command line argument (with or without the "#" prefix):
@@ -30,6 +30,16 @@ export CLICKUP_REDIRECT_PORT=9999  (optional, CLI will default to port 4321, jus
     clickup get task 123456 -f         <short>
     clickup get task 123456 --file     <long/explicit>
     ```
+1. If Clickup space is using custom task IDs, set the `CLICKUP_TEAM_ID` env variable to your organization team ID, and pass the -c flag:
+    ```
+    clickup get task CUSTOM-1234 -c        <short>
+    clickup get task CUSTOM-1234 --custom  <long/explicit>
+    ```
+1. To include sub-tasks in the JSON output, add the -s flag:
+    ```
+    clickup get task 123456 -s
+    clickup get task 123456 --subtasks
+    ```
 
 ### Logout
 1. ClickupCLI will save your authentication token in $HOME/.clickup/config.yaml.  To delete the token issue the logout subcommand: