Update Readme with links to issue Shopify#55 and PR Shopify#63

For better visibility and to minimize the number of "duplicate issues" created by people trying the extension, let visitors know ahead about the two known bugs: not being able to profile a development store, and not being able to profile a Storefront Renderer rendered store.

README.md

@@ -95,6 +95,8 @@ If you see this error, it may be because of one of the following conditions:
   * Your account does not have access to the current store you are trying to profile.
   * You might be trying to profile a checkout page, which is not supported by this extension.
   * There was an unhandled error in the request, e.g. timeout, lost connection, etc.
+  * You might be trying to profile a development store. We can't profile it yet when you're logged in as the owner. See [issue #55](https://github.com/Shopify/shopify-theme-inspector/issues/55) for a workaround.
+  * This might be a known bug: If your store uses Storefront Renderer, we can't profile it yet. We're working hard to fix it. Subscribe to [pull request #63](https://github.com/Shopify/shopify-theme-inspector/pull/63) to get updates.
 
 If it was none of the errors above you can right click on Shopify DevTools , inspect page, and view console for error details.