Improvements in the docs of Neptune 3

As discussed copying this from the internal Confluence:

• Instrument Cluster says "Neptune 3 UI's remote settings server" which does not exist anymore. Moreover, tell-tales are not shown by default on startup, they are started by simulation after a certain while  and can be controlled only via the Companion App. 
• "Home button" is not mentioned on App Launcher.
• App Launcher. does not mention that the list of apps is automatically populated when Neptune starts first time and more apps are added when apps are installed.
• It is not mentioned in App Widgets that one widget remains and this is alway the bottom one.
• The icon on a widget to maximise an app is not mentioned in App Widgets. 
• It is not mentioned in App Widgets that it is possible to resize widgets
• It is not mentioned that one widget is always present and cannot be removed
• Instrument Cluster does not mention the a default simulation started on start-up
• Center Console Display  - the first paragraph might be confusing since it might be understood as we would fade out the borders btw processes. We actually do this on the UI only, and we do this since the end-user is not interested in processes, rather a fluent and coherent appearance of the whole UI even if the actual content comes from different apps running in separate processes.
• Center Console Display should explain Widgets earlier than now in the section "App Widget", since widgets are mentioned before they are explained.
• it is not mentioned how Neptune looks like and runs when it is started on the desktop
• Volume control is not mentioned
• The Sheet app should be mentioned IMHO since compared to other apps it is really related to the app development
• On the System UI page this one should be re-tested "However, if no widgets were selected before Neptune 3 UI stopped, then when Neptune 3 UI restarts, it loads the default set of applications, such as the Calendar app, Music app, and Phone app"
• System Dialog page might mention that numbers from the GPU performance and if it is used then the numbers from the CPU performance should be taken as absolute numbers, since visulization of these values takes performance as well
• System Dialog page mentions "qtdaig" tool which is actually spelled in small letters. It is not documented in Qt though, only mentioned on a few pages
• It might make sense to mention the new "Develop the Parking App" tutorial in "Related Information" of  Middleware 
• It might make sense to add a screenshot of the Companion App on the page Companion App 
• Application Anatomy mentions the Camera app which is not upstream and is not documented
• Application Popups mentions the Sheets App which is not documented
• The "Sheets App" section on "Application Popups" is not formatted as a header 
• The "ctrl-n" shortcut mentioned in "System Notifications" on Application Requests is not documented on Keyboard Shortcut
• It might make sense mentioning of the "on-the-flight" LRT-RTL switching of the UI layout when the language is switched between Arabic and any other language in General Settings Application. 
• The titles "Vehicle Integration with Qt 3D" and "Vehicle Integration with Qt 3D Studio" in 3D Integration should be IMHO changed to "Vehicle 3D Model Integration with <...>", since we do not integrate the whole vehicle, only its 3D model.