Removed Board page, samples, and references to it (#4810)

* Removed Board page, samples, and references to it.

* Added missing LumoUtility import.

* Removed Board package version from package.json

* Removed Board mention in MPR docs

* Changed mention of Board in Flow WC Java API docs to mention Grid instead

* Revert "Changed mention of Board in Flow WC Java API docs to mention Grid instead"

This reverts commit a336621.

Author: rolfsmeds

articles/components/board/board.png

@@ -645,17 +645,6 @@ include::app-layout/index.adoc[tag=description]
 <<{components-path-prefix}app-layout#,See App Layout>>
 
 
-[.component-card.commercial]
-=== Board
-
-image::{components-path-prefix}board/board.png["", opts=inline, role="banner"]
-
-include::board/index.adoc[tag=description]
-
-[.sr-only]
-<<{components-path-prefix}board#,See Board>>
-
-
 [.component-card.commercial]
 === Dashboard
 

articles/components/board/index.adoc

@@ -88,7 +88,7 @@ The following table contains an overview of the responsive features of each comp
 |Component|Responsive Features
 
 |<</components/app-layout#,App Layout>>|The navigation drawer can be displayed as an overlay or bottom navbar. The drawer automatically collapses to a hamburger menu on small viewports.
-|<</components/board#,Board>>|The layout is automatically optimized and adjusted based on the screen size.
+|<</components/dashboard#,Dashboard>>|The layout is automatically optimized and adjusted based on the screen size.
 |<</components/charts#,Charts>>|All chart types can be configured to fill any available space. Charts scale in real time when the container size changes.
 |<</components/context-menu#,Context Menu>>|The menu is fixed to the bottom of the screen on small viewports.
 |<</components/crud#,CRUD>>|The editor is always shown as an overlay on small viewports.

articles/components/index.adoc

@@ -112,11 +112,6 @@ Java 8+ is required. Since the application managed by the MPR is a Flow applicat
 Old browsers aren't supported. Browser support for MPR applications is based on the running Vaadin version. For Vaadin 14, those include Internet Explorer 11 with transpilation, and evergreen browsers (the latest versions of Chrome, Firefox, Opera, Safari and Edge). For Vaadin 15 and newer, IE11 and Safari versions older than 13 are no longer supported.
 
 
-== Vaadin Board
-
-Vaadin Board 1.1.0 isn't supported. Since Vaadin Board 1.1.0 requires Polymer 2, and Vaadin {vaadin-version} requires Lit, Vaadin Board isn't compatible with Vaadin {vaadin-version} and can't be used as a legacy component.
-
-
 == Z-Indexes
 
 Z-indexes of the modern Vaadin Design System aren't aligned with legacy. Components using overlays and popups in Vaadin 7 and Vaadin 8 are organized in different z-indexes from similar components in the modern Vaadin Design System. Thus it's possible that some combinations of them don't work.