docs: fix asset input path

Closes #12219

Author: alan-agius4

docs/documentation/stories/asset-configuration.md

@@ -20,7 +20,7 @@ The array below does the same as the default one:
 ```json
 "assets": [
   { "glob": "**/*", "input": "src/assets/", "output": "/assets/" },
-  { "glob": "favicon.ico", "input": "/src", "output": "/" },
+  { "glob": "favicon.ico", "input": "src/", "output": "/" },
 ]
 ```
 
@@ -50,4 +50,4 @@ The contents of `node_modules/some-package/images/` will be available in `dist/s
 ## Writing assets outside of `dist/`
 
 Because of the security implications, the CLI will always refuse to write files outside of
-the project output path.
+the project output path.