Docs: move STARTS/ENDS_WITH under string functions in the docs (#107867)

This moves the STARTS_WITH and ENDS_with under the strings functions
section (as they're not operators).

docs/reference/esql/functions/operators.asciidoc

@@ -13,11 +13,9 @@ Boolean operators for comparing against one or multiple expressions.
 * <<esql-logical-operators>>
 * <<esql-predicates>>
 * <<esql-cidr_match>>
-* <<esql-ends_with>>
 * <<esql-in-operator>>
 * <<esql-like-operator>>
 * <<esql-rlike-operator>>
-* <<esql-starts_with>>
 // end::op_list[]
 
 include::binary.asciidoc[]
@@ -25,8 +23,6 @@ include::unary.asciidoc[]
 include::logical.asciidoc[]
 include::predicates.asciidoc[]
 include::cidr_match.asciidoc[]
-include::ends_with.asciidoc[]
 include::in.asciidoc[]
 include::like.asciidoc[]
 include::rlike.asciidoc[]
-include::starts_with.asciidoc[]

docs/reference/esql/functions/string-functions.asciidoc

@@ -9,6 +9,7 @@
 
 // tag::string_list[]
 * <<esql-concat>>
+* <<esql-ends_with>>
 * <<esql-from_base64>>
 * <<esql-left>>
 * <<esql-length>>
@@ -18,6 +19,7 @@
 * <<esql-right>>
 * <<esql-rtrim>>
 * <<esql-split>>
+* <<esql-starts_with>>
 * <<esql-substring>>
 * <<esql-to_base64>>
 * <<esql-to_lower>>
@@ -26,6 +28,7 @@
 // end::string_list[]
 
 include::layout/concat.asciidoc[]
+include::ends_with.asciidoc[]
 include::layout/from_base64.asciidoc[]
 include::layout/left.asciidoc[]
 include::layout/length.asciidoc[]
@@ -35,6 +38,7 @@ include::layout/replace.asciidoc[]
 include::layout/right.asciidoc[]
 include::layout/rtrim.asciidoc[]
 include::layout/split.asciidoc[]
+include::starts_with.asciidoc[]
 include::layout/substring.asciidoc[]
 include::layout/to_base64.asciidoc[]
 include::layout/to_lower.asciidoc[]