expose useful libs (#4489)

* expose useful libs
* Update UIPluginApi.md

ui/v2.5/src/docs/en/Manual/UIPluginApi.md

@@ -12,6 +12,10 @@ An example using various aspects of `PluginApi` may be found in the source code
 
 An instance of the React library.
 
+### `ReactDOM`
+
+An instance of the ReactDOM library.
+
 ### `GQL`
 
 This namespace contains the generated graphql client interface. This is a low-level interface. In many cases, `StashService` should be used instead.
@@ -25,6 +29,8 @@ This namespace contains the generated graphql client interface. This is a low-le
 - `Intl`
 - `FontAwesomeRegular`
 - `FontAwesomeSolid`
+- `Mousetrap`
+- `MousetrapPause`
 
 ### `register`
 

ui/v2.5/src/pluginApi.tsx

@@ -1,5 +1,8 @@
 import React from "react";
+import ReactDOM from "react-dom";
 import * as ReactRouterDOM from "react-router-dom";
+import Mousetrap from "mousetrap";
+import MousetrapPause from "mousetrap-pause";
 import NavUtils from "./utils/navigation";
 import { HoverPopover } from "./components/Shared/HoverPopover";
 import { TagLink } from "./components/Shared/TagLink";
@@ -97,6 +100,7 @@ export function RegisterComponent(component: string, fn: Function) {
 }
 export const PluginApi = {
   React,
+  ReactDOM,
   GQL,
   libraries: {
     ReactRouterDOM,
@@ -105,6 +109,8 @@ export const PluginApi = {
     Intl,
     FontAwesomeRegular,
     FontAwesomeSolid,
+    Mousetrap,
+    MousetrapPause,
   },
   register: {
     // register a route to be added to the main router