Readme improvement suggestions

[marcakafoddex]

First of all, thank you for your awesome work on glfm!

Then, a suggestion. As a seasoned game developer, but fairly big noob at Android, I had a lot of trouble getting the example to work based on your instructions in the readme

I was using the latest AndroidStudio downloaded today (version 3.5.2) and followed your instructions to the letter. So I replaced the android manifest and the app/build.gradle with what you supply, but it didn't work at all. I had nothing but weird linking errors (in xml files...) and tried to fix things for about 2 hours.

Frustrated, I started from scratch with a new and fresh "No Activity" project in AndroidStudio, and tried careful copy/pasting from your app/build.gradle file instead. I just copied android/defaultConfig/externalNativeBuild, android/sourceSets.main and android/externalNativeBuild, and it worked instantly!

So my recommendation would be to NOT tell people to bluntly replace their app/build.gradle file, but copy/paste the necessary sections as mentioned above instead. It's a lot better advice as messing with SDK versions and dependencies will get you in a world of hurt!

[brackeen]

Thanks for the feedback, the readme has been updated with these suggestions.