Add manual ignore flag

Signed-off-by: Daniel Henry <iamdanhenry@gmail.com>

README.md

@@ -23,7 +23,7 @@ uv tool uninstall dumpy
 
 # Usage
 ```
-usage: dumpy.py [-h] [--no-gitignore] [--include-git-dir] [--no-clipboard] [--no-stats]
+usage: dumpy.py [-h] [--no-gitignore] [--include-git-dir] [--no-clipboard] [--no-stats] [--ignore IGNORE]
 
 Dumpy: A tool for providing a text representation of a project formatted in a way that LLMs will understand.
 
@@ -33,6 +33,7 @@ options:
   --include-git-dir  Include the .git directory in the output
   --no-clipboard     Skip putting content into the clipboard and ouput directly to the console
   --no-stats         Skip printing stats at the end of the output
+  --ignore IGNORE    Comma separated list of patterns to ignore.
   ```
 
 # Notes