Added CheerpJ extension docs (Debug & File handling)

[rijulshrestha]

No description provided.

[epanholz]

Great job already! The overall flow of the new pages is really nice and they are not too overloaded.

Debug page input:

• I am not to happy with the title, something like "How to debug the extension" might be better
• Please prompt users to enable the debug setting before loading the application or to reload the page after enabling the setting. Otherwise it won't take effect.
• Please include the instructions on how to collect a console log and har file in the extension pages. Clicking to another page is annoying for users. And we need to add specific instructions for each extension. For the JNLPRunner we can prompt users to open the dev tools on the "start application" page. To make sure the logs are complete. And for the AppletRunner we need to prompt users to either reload the page after opening the dev tools or to enable the extension only after the dev tools are open. This helps with getting incomplete logs from users. It's a bit annoying that we will have such similar pages, but it can help us save some time in the long run.

File pages:

• We can link to the explanation guide here at the top of the page
• For the upload button we should add context that it will only be available once an applet/application is already running
• We can also add that if users can't see the popup icon they need to ping the extension
• Please remove mentions of JFileChooser, there is other classes that work the same. We can just mention it once like this "Java File Dialog (for example JFileChooser) and then just say File Dialog. Also the upload icon will be present on any window/frame/dialog that opens. It's part of the title bar.