dry run mode docs

Author: GrantBirki

README.md

@@ -50,6 +50,14 @@ Combine all open pull requests in a repository that are created by dependabot:
 gh combine owner/repo --dependabot
 ```
 
+### In Dry Run Mode
+
+You can run in dry run mode to see what would happen without actually creating a pull request or combining any pull requests:
+
+```bash
+gh combine owner/repo --dry-run
+```
+
 ### With Passing CI
 
 Combine multiple pull requests together but only if their CI checks are passing:

internal/cmd/root.go

@@ -115,6 +115,7 @@ func NewRootCmd() *cobra.Command {
       gh combine owner/repo --add-assignees octocat,hubot        # Assign users to the new PR
     
       # Additional options
+	  gh combine owner/repo --dry-run                           # Simulate the actions without making any changes
       gh combine owner/repo --autoclose                         # Close source PRs when combined PR is merged
 	  gh combine owner/repo --base-branch main                  # Use a different base branch for the combined PR
 	  gh combine owner/repo --no-color                          # Disable color output