Add Language: OpenCypher

## Language name

Cypher, OpenCypher - the query language for Neo4j.

> Cypher is a [declarative](https://en.wikipedia.org/wiki/Declarative_programming) graph query language that allows for expressive and efficient data querying in a property graph.[[1]](https://en.wikipedia.org/wiki/Cypher_(query_language)#cite_note-cypher-introduction-1)
>
> Cypher was largely an invention of Andrés Taylor while working for Neo4j, Inc. (formerly Neo Technology) in 2011.[[2]](https://en.wikipedia.org/wiki/Cypher_(query_language)#cite_note-cypher-paper-2) Cypher was originally intended to be used with the graph database [Neo4j](https://en.wikipedia.org/wiki/Neo4j), but was opened up through the openCypher project in October 2015.[[3]](https://en.wikipedia.org/wiki/Cypher_(query_language)#cite_note-3)
>
> The language was designed with the power and capability of [SQL](https://en.wikipedia.org/wiki/SQL) (standard query language for the [relational database model](https://en.wikipedia.org/wiki/Relational_model)) in mind, but Cypher was based on the components and needs of a database built upon the concepts of [graph theory](https://en.wikipedia.org/wiki/Graph_theory). In a graph model, data is structured as nodes ([vertices](https://en.wikipedia.org/wiki/Vertex_(graph_theory)) in math and network science) and relationships (edges in math and network science) to focus on how entities in the data are connected and related to one another.

_source: https://en.wikipedia.org/wiki/Cypher_(query_language)_

* https://github.com/opencypher/openCypher
* https://neo4j.com/developer/cypher
* Full langage doc --> https://neo4j.com/docs/cypher-manual/current

More specific resources re: Cypher's Grammar :)

* Railroad docs: https://s3.amazonaws.com/artifacts.opencypher.org/railroad/Cypher.html
* EBNF: https://s3.amazonaws.com/artifacts.opencypher.org/cypher.ebnf
* ANTLR4: https://s3.amazonaws.com/artifacts.opencypher.org/Cypher.g4

existing syntax highlighting packages:

* https://github.com/highlightjs/highlightjs-cypher
* https://github.com/jakeboone02/cypher-query-language/blob/master/README.md

## URL of example repository

## URL of syntax highlighting grammar

## Most popular extensions

## Detected language