layout.margin: Fix the documentation

lib/wibox/layout/margin.lua

@@ -14,7 +14,7 @@ local cairo = require("lgi").cairo
 
 local margin = { mt = {} }
 
---- Draw a margin layout
+-- Draw a margin layout
 function margin:draw(_, cr, width, height)
     local x = self.left
     local y = self.top
@@ -35,7 +35,7 @@ function margin:draw(_, cr, width, height)
     end
 end
 
---- Layout a margin layout
+-- Layout a margin layout
 function margin:layout(_, width, height)
     if self.widget then
         local x = self.left
@@ -47,7 +47,7 @@ function margin:layout(_, width, height)
     end
 end
 
---- Fit a margin layout into the given space
+-- Fit a margin layout into the given space
 function margin:fit(context, width, height)
     local extra_w = self.left + self.right
     local extra_h = self.top + self.bottom
@@ -72,13 +72,13 @@ function margin:set_widget(widget)
     self:emit_signal("widget::layout_changed")
 end
 
---- Get the number of children element
+-- Get the number of children element
 -- @treturn table The children
 function margin:get_children()
     return {self.widget}
 end
 
---- Replace the layout children
+-- Replace the layout children
 -- This layout only accept one children, all others will be ignored
 -- @tparam table children A table composed of valid widgets
 function margin:set_children(children)
@@ -86,6 +86,7 @@ function margin:set_children(children)
 end
 
 --- Set all the margins to val.
+-- @tparam number val The margin value
 function margin:set_margins(val)
     if self.left   == val and
        self.right  == val and
@@ -101,7 +102,8 @@ function margin:set_margins(val)
     self:emit_signal("widget::layout_changed")
 end
 
---- Set the margins color to color
+--- Set the margins color to create a border.
+-- @param color A color used to fill the margin.
 function margin:set_color(color)
     self.color = color and gcolor(color)
     self:emit_signal("widget::redraw_needed")