add doc for apache/echarts#20782

Author: sz-p

en/option/partial/mark-area.md

@@ -228,6 +228,14 @@ x value on screen coordinate system, can be pixel number (like `5`), or percent
 
 y value on screen coordinate system, can be pixel number (like `5`), or percent value (like `'20%'`).
 
+#${prefix} z2(number)
+
+{{ use: partial-version(
+    version = "6.0.0"
+) }}
+
+Specify the relationship of overlap between graphic elements. A bigger value means higher.
+
 #${prefix} value(number)
 
 value of the item, not necessary.

en/option/partial/mark-line.md

@@ -288,6 +288,14 @@ X position according to container, in pixel.
 
 Y position according to container, in pixel.
 
+#${prefix} z2(number)
+
+{{ use: partial-version(
+    version = "6.0.0"
+) }}
+
+Specify the relationship of overlap between graphic elements. A bigger value means higher.
+
 #${prefix} xAxis(number|string)
 
 Markline at x at given value, which only works for single data item. Example:

en/option/partial/mark-point.md

@@ -167,6 +167,14 @@ X position according to container, in pixel.
 
 Y position according to container, in pixel.
 
+###${prefix} z2(number)
+
+{{ use: partial-version(
+    version = "6.0.0"
+) }}
+
+Specify the relationship of overlap between graphic elements. A bigger value means higher.
+
 ###${prefix} value(number)
 
 Label value, which can be ignored.

zh/option/partial/mark-area.md

@@ -223,6 +223,14 @@ data: [
 
 相对容器的屏幕 y 坐标，单位像素，支持百分比形式，例如 `'20%'`。
 
+#${prefix} z2(number)
+
+{{ use: partial-version(
+    version = "6.0.0"
+) }}
+
+指定图形元素间的覆盖关系。数值越大，越在层叠的上方。
+
 #${prefix} value(number)
 
 标域值，可以不设。

zh/option/partial/mark-line.md

@@ -287,6 +287,14 @@ data: [
 
 相对容器的屏幕 y 坐标，单位像素。
 
+#${prefix} z2(number)
+
+{{ use: partial-version(
+    version = "6.0.0"
+) }}
+
+指定图形元素间的覆盖关系。数值越大，越在层叠的上方。
+
 #${prefix} xAxis(number|string)
 
 x 值为给定值的标记线，仅对数据值是一项的设置有效。例如：

zh/option/partial/mark-point.md

@@ -167,6 +167,14 @@ data: [{{ if: ${hasType} }}
 
 相对容器的屏幕 y 坐标，单位像素。
 
+###${prefix} z2(number)
+
+{{ use: partial-version(
+    version = "6.0.0"
+) }}
+
+指定图形元素间的覆盖关系。数值越大，越在层叠的上方。
+
 ###${prefix} value(number)
 
 标注值，可以不设。