docs(readme): info about supported browsers

Author: Kurdi Szabolcs

README.md

@@ -30,16 +30,23 @@ Promise.all([
 
 ## caveats
 
-* Loading is not sequential
-* Style loading may not work with mobile borwsers or in old Safari?
-  [Followup is here](https://github.com/w3core/import.js/issues/2).
+* Loading is not sequential of course. In the above example "main.js" may be parsed
+  before "highlighter.js". If you want in order loading, use a sequential promise
+  executor or a then chain.
+* Style loading may not work with very old mobile borwsers.
+  [Followup is here](https://github.com/w3core/import.js/issues/2), see addendum below.
 * The e2e test runner breaks (in phantom, but the test.html works in the browser)
   this is caused by an old phantomjs version in the _mocha-phantomjs_ package.
-  [Issue is here](https://github.com/nathanboktae/mocha-phantomjs/issues/248)
+  [Issue is here](https://github.com/nathanboktae/mocha-phantomjs/issues/248). Solutions:
   * either wait for the upstream package to be updated 
   * or update the binary manually (inside node_modules)
 
 ## exposed test
 
 Temporarily the e2e standalone test page has been exposed to [docs](./docs) and is made
-available as a github page. TODO: browserstack?
+available as a [github page](https://prepair.github.io/basic-loader/).
+TODO: use browserstack or smg similar?
+
+- [x] Chrome/30 Mobile Safari/537.6 (android 4.4.2), from [2013](https://en.wikipedia.org/wiki/Safari_version_history)
+- [x] iOS 10.2.1 (vanilla iphone 6)
+- [x] Firefox 51.0.3 (android 4.4.2)