clarify how to exclude a directory

Author: mmarchetti

README.md

@@ -278,12 +278,18 @@ rsconnect deploy api flask-api/ data.csv
 
 Since deploying an API or application starts at a directory level, there will be times
 when some files under that directory subtree should not be included in the deployment
-or manifest. Use the `--exclude` option to specify files to exclude. The `--exclude` option may be repeated, and may include a glob pattern.
+or manifest. Use the `--exclude` option to specify files or directories to exclude.
 
 ```bash
 rsconnect deploy dash --exclude dash-app-venv --exclude TODO.txt dash-app/
 ```
 
+You can exclude a directory by naming it:
+```bash
+rsconnect deploy dash --exclude dash-app-venv --exclude output/ dash-app/
+```
+
+The `--exclude` option may be repeated, and may include a glob pattern.
 You should always quote a glob pattern so that it will be passed to `rsconnect` as-is
 instead of letting the shell expand it. If a file is specifically listed as an extra
 file that also matches an exclusion pattern, the file will still be included in the