Create documentation for partialComparisonExpression

We need to add documentation partialComparisonExpression for those that are [supported by our grammar](https://github.com/memgraph/memgraph/blob/master/src/query/frontend/opencypher/grammar/Cypher.g4).

E.g.

```
CREATE (:User {name: “Katarina”})
CREATE (:User {name: “Karmen”})
MATCH (u:User), (b:User)
WHERE u.name <> b.name
RETURN u, b
```