doc: Add examples for vertical and labelled progressbar

lib/wibox/widget/progressbar.lua

@@ -1,11 +1,20 @@
 ---------------------------------------------------------------------------
 --- A progressbar widget.
 --
+-- To add text on top of the progressbar, a `wibox.layout.stack` can be used:
+--
+--@DOC_wibox_widget_progressbar_text_EXAMPLE@
+--
+-- To display the progressbar vertically, use a `wibox.container.rotate` widget:
+--
+--@DOC_wibox_widget_progressbar_vertical_EXAMPLE@
+--
 -- By default, this widget will take all the available size. To prevent this,
 -- a `wibox.container.constraint` widget or the `forced_width`/`forced_height`
 -- properties have to be used.
 --
 --@DOC_wibox_widget_defaults_progressbar_EXAMPLE@
+--
 -- @author Julien Danjou <julien@danjou.info>
 -- @copyright 2009 Julien Danjou
 -- @release @AWESOME_VERSION@

tests/examples/wibox/widget/progressbar/text.lua

@@ -0,0 +1,25 @@
+local parent = ... --DOC_NO_USAGE --DOC_HIDE
+local wibox  = require("wibox") --DOC_HIDE
+local beautiful = require("beautiful") --DOC_HIDE
+
+parent:add( --DOC_HIDE
+
+    wibox.widget {
+        {
+            max_value     = 1,
+            value         = 0.5,
+            forced_height = 20,
+            forced_width  = 100,
+            paddings      = 1,
+            border_width  = 1,
+            border_color  = beautiful.border_color,
+            widget        = wibox.widget.progressbar,
+        },
+        {
+            text   = "50%",
+            widget = wibox.widget.textbox,
+        },
+        layout = wibox.layout.stack
+    }
+
+) --DOC_HIDE

tests/examples/wibox/widget/progressbar/vertical.lua

@@ -0,0 +1,18 @@
+local parent = ... --DOC_NO_USAGE --DOC_HIDE
+local wibox  = require("wibox") --DOC_HIDE
+
+parent:add( --DOC_HIDE
+
+    wibox.widget {
+        {
+            max_value     = 1,
+            value         = 0.33,
+            widget        = wibox.widget.progressbar,
+        },
+        forced_height = 100,
+        forced_width  = 20,
+        direction     = "east",
+        layout        = wibox.container.rotate,
+    }
+
+) --DOC_HIDE