add the md files from the docs repo to start updating them to v8

docs/widgets/objmask.md

@@ -0,0 +1,70 @@
+```eval_rst
+.. include:: /header.rst 
+:github_url: |github_link_base|/widgets/objmask.md
+```
+# Object mask (lv_objmask)
+
+## Overview
+The *Object mask* is capable of add some mask to drawings when its children is drawn. 
+
+## Parts and Styles
+The Object mask has only a main part called `LV_OBJMASK_PART_BG` and it uses the typical background style properties. 
+
+## Usage
+
+### Adding mask
+
+Before adding a mask to the *Object mask* the mask should be initialized:
+```c
+    lv_draw_mask_<type>_param_t mask_param;
+    lv_draw_mask_<type>_init(&mask_param, ...);
+    lv_objmask_mask_t * mask_p = lv_objmask_add_mask(objmask, &mask_param);
+```
+
+Lvgl supports the following mask types:
+- **line** clip the pixels on the top/bottom left/right of a line. Can be initialized from two points or a point and an angle:
+- **angle** keep the pixels only between a given start and end angle 
+- **radius** keep the pixel only inside a rectangle which can have radius (can for a circle too). Can be inverted to keep the pixel outside of the rectangle.
+- **fade** fade vertically (change the pixels opacity according to their y position)
+- **map** use an alpha mask (a byte array) to describe the pixels opacity.
+
+The coordinates in the mask are relative to the Object. That is if the object moves the masks move with it.
+
+For the details of the mask *init* function see the [API](#api) documentation below.
+
+### Update mask
+AN existing mask can be updated with `lv_objmask_update_mask(objmask, mask_p, new_param)`, where `mask_p` is return value of `lv_objmask_add_mask`.
+
+### Remove mask
+A mask can be removed with `lv_objmask_remove_mask(objmask, mask_p)`
+
+## Events
+Only the [Generic events](../overview/event.html#generic-events) are sent by the object type.
+
+Learn more about [Events](/overview/event).
+
+## Keys
+No *Keys* are processed by the object type.
+
+Learn more about [Keys](/overview/indev).
+
+## Example
+
+```eval_rst
+
+.. include:: /lv_examples/src/lv_ex_widgets/lv_ex_objmask/index.rst
+
+
+```
+
+## API
+
+```eval_rst
+
+.. doxygenfile:: lv_objmask.h
+  :project: lvgl
+  
+.. doxygenfile:: lv_draw_mask.h
+  :project: lvgl
+
+```