docs(scrollbar): add doc about scrollbar

docs/cn/layers/ui.md

@@ -22,16 +22,16 @@ lang: zh
 ```toml
 [[layers]]
   name = "ui"
-    enable_sidebar = false
-    enable_scrollbar = false
-    enable_indentline = true
-    enable_cursorword = false
-    indentline_char = '|'
-    conceallevel = 0
-    concealcursor = ''
-    cursorword_delay = 50
-    cursorword_exclude_filetype = []
-    indentline_exclude_filetype = []
+  enable_sidebar = false
+  enable_scrollbar = false
+  enable_indentline = true
+  enable_cursorword = false
+  indentline_char = '|'
+  conceallevel = 0
+  concealcursor = ''
+  cursorword_delay = 50
+  cursorword_exclude_filetype = []
+  indentline_exclude_filetype = []
 ```
 
 ## 启用模块

docs/documentation.md

@@ -26,6 +26,7 @@ description: "General documentation about how to use SpaceVim, including the qui
   - [Colorschemes](#colorschemes)
   - [Font](#font)
   - [Mouse](#mouse)
+  - [Scrollbar](#scrollbar)
   - [UI Toggles](#ui-toggles)
   - [Statusline](#statusline)
   - [Tabline](#tabline)
@@ -570,6 +571,17 @@ endfunction
 
 Read `:h 'mouse'` for more info.
 
+### Scrollbar
+
+The scrollbar is disabled by default. To enable the scrollbar,
+you need to change `enable_scrollbar` option in [ui layer](../layers/ui/).
+
+```
+[[layers]]
+  name = "ui"
+  enable_scrollbar = true
+```
+
 ### UI Toggles
 
 Some UI indicators can be toggled on and off (toggles start with t and T):

docs/layers/ui.md

@@ -21,16 +21,16 @@ and this layer is enabled by default with following options:
 ```toml
 [[layers]]
   name = "ui"
-    enable_sidebar = false
-    enable_scrollbar = false
-    enable_indentline = true
-    enable_cursorword = false
-    indentline_char = '|'
-    conceallevel = 0
-    concealcursor = ''
-    cursorword_delay = 50
-    cursorword_exclude_filetype = []
-    indentline_exclude_filetype = []
+  enable_sidebar = false
+  enable_scrollbar = false
+  enable_indentline = true
+  enable_cursorword = false
+  indentline_char = '|'
+  conceallevel = 0
+  concealcursor = ''
+  cursorword_delay = 50
+  cursorword_exclude_filetype = []
+  indentline_exclude_filetype = []
 ```
 
 ## Install