Add a Language Reference section to the OML Spec

[melaasar]

User Story

As an OML modeler, I want the OML spec to have a Language Reference section, so that I can learn the language and see the value.

Acceptance Criteria

The OML spec has a Language Reference section that:

• Describe how to model basic topics:
  • Describe the basic organizational features ,
  • Describe how to create a simple vocabulary with concept, scalar property and relation
  • Describe how to create a simple vocabulary bundle
  • Describe how to create a simple description with concept instance with scalar property and link assertions
  • Describe how to create a simple description bundle
• Describe how to model advanced topics:
  • Advanced ontology organization
  • Advanced vocabulary constructs
  • Advanced axioms
  • Relation Instances
  • Rules

[melaasar]

OML spec now has a language reference section:
http://www.opencaesar.io/oml/#Language-Reference