Make main page examples simple and clear

[shamansir]

The major problem of RPD these days is that some users don't get why RPD or Flow Programming could be useful for them. So may be easier steps and simple examples could help them to get the idea and to think on how they may apply it to their projects.

Like:

• This is a Node;
• This is a Node with a control inside;
• This is how it looks like when it has Inlets;
• This is how it looks like when it has Outlets;
• This is another Node;
• Try to connect them;
• ...
• This is the Node sending a stream of data;
• ...