Add IYP browser to the IYP website

[dpgiakatos]

This PR adds the IYP browser info and link to the IYP website.

[romain-fontugne]

@dpgiakatos @m-appel are you convinced that the IYP browser is finalized enough that it could entirely replace the default Neo4J browser?

From my latest experience with the browser:

• I think there is a few features that are in neo4j browser but not in iyp browser (e.g. having a list of all node/relationship types and clicking on this to get a "template" query) that overall makes it less easy to use.
• For people that are used to cypher/neo4j it seems to be another tool to learn so I think it would be better to at least have the option between the two.

So I think it would be better for now if the iyp browser is an opt-in option rather than the default and giving extra steps to reach the currently default tool.

[dpgiakatos]

I have removed all the IYP Browser links from the website. I only replaced the images in the Example Queries section with iFrames from the IYP Browser.