Keep explanations of features separated from java examples

[santo-it]

Important task to improve the documentation

When we describe / explain things, we should explain them assuming that the reader has no knowledge of java

We should explain how the things work in general and then we may add subsections to say how to do that specific thing with java, with SQL or using any other method

Right now too often we explain things adding java examples, or immediately mentioning java - things that should be avoided

[santo-it]

see also https://github.com/orientechnologies/orientdb-docs/issues/269