New data modeling tutorial (#437)

* New data modeling tutorial

* removing unused image

* fixing cypher

* Apply suggestions from code review

Co-authored-by: Jessica Wright <[email protected]>

* updates after review

* Apply suggestions from code review

Co-authored-by: Jessica Wright <[email protected]>

* updates after review

* updates after review

* Apply suggestions from code review

Co-authored-by: Martin O'Hanlon <[email protected]>

* updates after review

* updates after review

* updates after review

---------

Co-authored-by: Jessica Wright <[email protected]>
Co-authored-by: Martin O'Hanlon <[email protected]>

Author: 3 people

modules/ROOT/content-nav.adoc

@@ -22,11 +22,10 @@
 * *Work with data*
 
 * xref:data-modeling/index.adoc[Model data]
-// ** xref:data-modeling/tutorial-data-modeling.adoc[]
+** xref:data-modeling/tutorial-data-modeling.adoc[Tutorial: Create a data model]
 ** xref:data-modeling/modeling-designs.adoc[]
 ** xref:data-modeling/relational-to-graph-modeling.adoc[]
 ** xref:data-modeling/modeling-tips.adoc[]
-** xref:data-modeling/graph-model-refactoring.adoc[]
 ** xref:data-modeling/data-modeling-tools.adoc[]
 
 * xref:data-import/index.adoc[Import data into Neo4j]