Support depthOffset in MD docs headings for nesting functions

Author: craigtaverner

docs/reference/query-languages/esql/_snippets/functions/layout/st_xmax.md

@@ -6,7 +6,7 @@
 * [`ST_X`](../../functions-operators/spatial-functions.md#esql-st_x)
 * [`ST_Y`](../../functions-operators/spatial-functions.md#esql-st_y)
 * [preview] [`ST_ENVELOPE`](../../functions-operators/spatial-functions.md#esql-st_envelope)
-* [preview] [`ST_XMAX`](../../functions-operators/spatial-functions.md#esql-st_xmax)
-* [preview] [`ST_XMIN`](../../functions-operators/spatial-functions.md#esql-st_xmin)
-* [preview] [`ST_YMAX`](../../functions-operators/spatial-functions.md#esql-st_ymax)
-* [preview] [`ST_YMIN`](../../functions-operators/spatial-functions.md#esql-st_ymin)
+  * [preview] [`ST_XMAX`](../../functions-operators/spatial-functions.md#esql-st_xmax)
+  * [preview] [`ST_XMIN`](../../functions-operators/spatial-functions.md#esql-st_xmin)
+  * [preview] [`ST_YMAX`](../../functions-operators/spatial-functions.md#esql-st_ymax)
+  * [preview] [`ST_YMIN`](../../functions-operators/spatial-functions.md#esql-st_ymin)

docs/reference/query-languages/esql/_snippets/functions/layout/st_xmin.md

@@ -70,6 +70,11 @@
      */
     String appendix() default "";
 
+    /**
+     * The heading depth of this function in the docs, relative to the normal depth of functions.
+     */
+    int depthOffset() default 0;
+
     /**
      * The position the function can appear in the language.
      */

docs/reference/query-languages/esql/_snippets/functions/layout/st_ymax.md

@@ -45,7 +45,8 @@ public class StXMax extends UnaryScalarFunction {
         returnType = "double",
         description = "Extracts the maximum value of the `x` coordinates from the supplied geometry.\n"
             + "If the geometry is of type `geo_point` or `geo_shape` this is equivalent to extracting the maximum `longitude` value.",
-        examples = @Example(file = "spatial_shapes", tag = "st_x_y_min_max")
+        examples = @Example(file = "spatial_shapes", tag = "st_x_y_min_max"),
+        depthOffset = 1  // So this appears as a subsection of ST_ENVELOPE
     )
     public StXMax(
         Source source,

docs/reference/query-languages/esql/_snippets/functions/layout/st_ymin.md

@@ -45,7 +45,8 @@ public class StXMin extends UnaryScalarFunction {
         returnType = "double",
         description = "Extracts the minimum value of the `x` coordinates from the supplied geometry.\n"
             + "If the geometry is of type `geo_point` or `geo_shape` this is equivalent to extracting the minimum `longitude` value.",
-        examples = @Example(file = "spatial_shapes", tag = "st_x_y_min_max")
+        examples = @Example(file = "spatial_shapes", tag = "st_x_y_min_max"),
+        depthOffset = 1  // So this appears as a subsection of ST_ENVELOPE
     )
     public StXMin(
         Source source,

docs/reference/query-languages/esql/_snippets/lists/spatial-functions.md

@@ -45,7 +45,8 @@ public class StYMax extends UnaryScalarFunction {
         returnType = "double",
         description = "Extracts the maximum value of the `y` coordinates from the supplied geometry.\n"
             + "If the geometry is of type `geo_point` or `geo_shape` this is equivalent to extracting the maximum `latitude` value.",
-        examples = @Example(file = "spatial_shapes", tag = "st_x_y_min_max")
+        examples = @Example(file = "spatial_shapes", tag = "st_x_y_min_max"),
+        depthOffset = 1  // So this appears as a subsection of ST_ENVELOPE
     )
     public StYMax(
         Source source,

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/FunctionInfo.java

@@ -45,7 +45,8 @@ public class StYMin extends UnaryScalarFunction {
         returnType = "double",
         description = "Extracts the minimum value of the `y` coordinates from the supplied geometry.\n"
             + "If the geometry is of type `geo_point` or `geo_shape` this is equivalent to extracting the minimum `latitude` value.",
-        examples = @Example(file = "spatial_shapes", tag = "st_x_y_min_max")
+        examples = @Example(file = "spatial_shapes", tag = "st_x_y_min_max"),
+        depthOffset = 1  // So this appears as a subsection of ST_ENVELOPE
     )
     public StYMin(
         Source source,