Update README VCR cassette path to match generator template

The VCR cassette_library_dir example was showing the old path with
framework-specific directory (spec/cypress/fixtures/vcr_cassettes).

Updated to use the default install_folder path (e2e/fixtures/vcr_cassettes)
which matches what the generator template creates.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: justin808

README.md

@@ -448,8 +448,7 @@ Add your VCR configuration to your `config/cypress_on_rails.rb`
 c.vcr_options = {
   hook_into: :webmock,
   default_cassette_options: { record: :once },
-  # It's possible to override cassette_library_dir using install_folder
-  cassette_library_dir: File.expand_path("#{__dir__}/../../spec/cypress/fixtures/vcr_cassettes")
+  cassette_library_dir: File.expand_path("#{__dir__}/../../e2e/fixtures/vcr_cassettes")
 }
 ```