docs: add stdin (#1769)

documentation/docs/guides/goose-cli-commands.md

@@ -171,7 +171,7 @@ Execute commands from an instruction file or stdin. Check out the [full guide](/
 
 **Options:**
 
-- **`-i, --instructions <FILE>`**: Path to instruction file containing commands
+- **`-i, --instructions <FILE>`**: Path to instruction file containing commands. Use - for stdin.
 - **`-t, --text <TEXT>`**: Input text to provide to Goose directly
 - **`-s, --interactive`**: Continue in interactive mode after processing initial input
 - **`-n, --name <NAME>`**: Name for this run session (e.g. 'daily-tasks')

documentation/docs/guides/running-tasks.md

@@ -48,6 +48,24 @@ Here's an example of an instruction file that runs a security audit on project d
 Save findings in 'security_audit.md' with severity levels highlighted.
 ```
 
+### With stdin
+You can also pass instructions to Goose using standard input via `-i -`. This is useful when you want to pipe commands from another tool or script into Goose.
+
+#### Simple echo pipe
+
+```bash
+echo "What is 2+2?" | goose run -i -
+```
+
+#### Multi-line instructions
+```bash
+cat << EOF | goose run -i -
+Please help me with these tasks:
+1. Calculate 15% of 85
+2. Convert 32°C to Fahrenheit
+EOF
+```
+
 ## Key Features
 
 ### Interactive Mode