Update readme

Author: jacobtyq

README.md

@@ -27,6 +27,8 @@ Your SVGs will be generated in `src/svg` folder
 6. Add your DEV_TOKEN from step 5 into `.env` file
 7. Run `node src/index.js` and your SVGs will be generated into `src/svg` folder
 
+### Filtering Private Components (starting with a . or a _)
+1. If you want to ignore / filter private components that start with a . or _, change the FILTER_PRIVATE_COMPONENTS variable to `true`. Thanks to [lennertVanSever for their contribution to this](https://github.com/jacobtyq/export-figma-svg/pull/27)
 ### Limitations
 
 Figma API has a fixed number of requests (rate limits) you can call per minute. This script will process a 20 requests per 45 seconds to avoid hitting that limit.