Fix 302/304 mixup (#260)

README.md

@@ -207,7 +207,7 @@ Import your module on the specific page. Note: you'll likely want to use a `cont
 
 ## Include a digest of the import map in your ETag
 
-If you're using [ETags](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/ETag) generated by Rails helpers like `stale?` or `fresh_when`, you need to include the digest of the import map into this calculation. Otherwise your application will return 302 cache responses even when your JavaScript assets have changed. You can avoid this with something like:
+If you're using [ETags](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/ETag) generated by Rails helpers like `stale?` or `fresh_when`, you need to include the digest of the import map into this calculation. Otherwise your application will return [304](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/304) cache responses even when your JavaScript assets have changed. You can avoid this with something like:
 
 ```ruby
 class ApplicationController < ActionController::Base