Restructuring Expressions (#697)

Current Expressions section is nested in Syntax chapter.

This PR will integrate them into more helpful places in the Manual (and
not create a new Expressions chapter, the title of which is too
vague/encompassing to be helpful).

Specific details:

- Expressions page deleted
- New Queries section (containing CASE and expressions in general from
old Expressions page)
- New Subqueries section (containing COLLECT, COUNT and EXISTS subquery
expressions from old Expressions page, and the CALL subquery page
(previously in Clauses)).
- Type predicate expressions moved from old Expressions page as its own
page in Values and types section

Additionally:
- New Queries section contains old Tutorial page from introduction
(renamed Basic queries)
- Queries section also contains new Core concepts pafe

---------

Co-authored-by: Stefano Ottolenghi <[email protected]>

modules/ROOT/content-nav.adoc

@@ -1,18 +1,13 @@
 * xref:introduction/index.adoc[]
 ** xref:introduction/cypher_overview.adoc[]
-** xref:introduction/cypher_tutorial.adoc[]
 ** xref:introduction/cypher_neo4j.adoc[]
 ** xref:introduction/cypher_aura.adoc[]
 
-* xref:syntax/index.adoc[]
-** xref:syntax/parsing.adoc[]
-** xref:syntax/naming.adoc[]
-** xref:syntax/expressions.adoc[]
-** xref:syntax/variables.adoc[]
-** xref:syntax/reserved.adoc[]
-** xref:syntax/parameters.adoc[]
-** xref:syntax/operators.adoc[]
-** xref:syntax/comments.adoc[]
+* xref:queries/index.adoc[]
+** xref:queries/concepts.adoc[]
+** xref:queries/basic.adoc[]
+** xref:queries/expressions.adoc[]
+** xref:queries/case.adoc[]
 
 * xref:clauses/index.adoc[]
 ** xref:clauses/clause_composition.adoc[]
@@ -31,7 +26,6 @@
 ** xref:clauses/remove.adoc[]
 ** xref:clauses/foreach.adoc[]
 ** xref:clauses/merge.adoc[]
-** xref:clauses/call-subquery.adoc[]
 ** xref:clauses/call.adoc[]
 ** xref:clauses/union.adoc[]
 ** xref:clauses/use.adoc[]
@@ -42,6 +36,12 @@
 ** xref:clauses/transaction-clauses.adoc#query-listing-transactions[SHOW TRANSACTIONS]
 ** xref:clauses/transaction-clauses.adoc#query-terminate-transactions[TERMINATE TRANSACTIONS]
 
+* xref:subqueries/index.adoc[]
+** xref:subqueries/call-subquery.adoc[]
+** xref:subqueries/subqueries-in-transactions.adoc[]
+** xref:subqueries/existential.adoc[]
+** xref:subqueries/count.adoc[]
+** xref:subqueries/collect.adoc[]
 
 * xref:patterns/index.adoc[]
 ** xref:patterns/concepts.adoc[]
@@ -57,7 +57,7 @@
 ** xref:values-and-types/lists.adoc[]
 ** xref:values-and-types/maps.adoc[]
 ** xref:values-and-types/casting-data.adoc[]
-
+** xref:values-and-types/type-predicate.adoc[]
 
 * xref:functions/index.adoc[]
 ** xref:functions/predicate.adoc[]
@@ -117,6 +117,15 @@
 *** xref:administration/access-control/limitations.adoc[]
 *** xref:administration/access-control/privileges-immutable.adoc[]
 
+* xref:syntax/index.adoc[]
+** xref:syntax/parsing.adoc[]
+** xref:syntax/naming.adoc[]
+** xref:syntax/variables.adoc[]
+** xref:syntax/reserved.adoc[]
+** xref:syntax/parameters.adoc[]
+** xref:syntax/operators.adoc[]
+** xref:syntax/comments.adoc[]
+
 * xref:deprecations-additions-removals-compatibility.adoc[]
 * xref:keyword-glossary.adoc[]