chore(docs): mentioning to delete the cache file

packages/docs/src/docs/editing-source-files.md

@@ -77,6 +77,10 @@ In the Node version of Pattern Lab you can modify the following configuration op
 }
 ```
 
+## Problems after changing the structure
+
+If you're doing bigger changes, especially to the file and folder structure, and recognize some errors on the console like, e.g. `TypeError: Cannot read property 'render' of undefined` or `Error building BuildFooterHTML`, it's recommended to stop pattern lab, delete the cache file `dependencyGraph.json` within the root of the project and start pattern lab again, as these changes might conflict with the existing cache structures.
+
 ## Watching for Source File Changes
 
-Manually generating the Pattern Lab website after each change can be cumbersome. The Node version of Pattern Lab comes with the ability to watch files in the `./source/` directory for changes and re-generate the site automatically. The Pattern Lab website can also be automatically reloaded..
+Manually generating the Pattern Lab website after each change can be cumbersome. The Node version of Pattern Lab comes with the ability to watch files in the `./source/` directory for changes and re-generate the site automatically. The Pattern Lab website can also be automatically reloaded.