feat(brightness): add brightness plugin (#4454)

* feat(brightness): add brightness plugin

* doc(brightness): update usage doc

src/@awesome-cordova-plugins/plugins/brightness/index.ts

@@ -0,0 +1,62 @@
+import { Injectable } from '@angular/core';
+import { Plugin, Cordova, AwesomeCordovaNativePlugin } from '@awesome-cordova-plugins/core';
+
+/**
+ * @name Brightness
+ * @description
+ * The Brightness plugin let you control the display brightness of your device.
+ *
+ * Requires Cordova plugin: `cordova-plugin-brightness`. For more info, please see the [Brightness plugin docs](https://github.com/mgcrea/cordova-plugin-brightness).
+ *
+ * @usage
+ * ```typescript
+ * import { Brightness } from '@awesome-cordova-plugins/brightness/ngx';
+ *
+ *
+ * constructor(private brightness: Brightness) { }
+ *
+ * ...
+ *
+ *
+ * let brightnessValue = 0.8;
+ * this.brightness.setBrightness(brightnessValue);
+ * ```
+ */
+@Plugin({
+  pluginName: 'Brightness',
+  plugin: 'cordova-plugin-brightness',
+  pluginRef: 'cordova.plugins.brightness',
+  repo: 'https://github.com/mgcrea/cordova-plugin-brightness',
+  platforms: ['Android', 'iOS'],
+})
+@Injectable()
+export class Brightness extends AwesomeCordovaNativePlugin {
+  /**
+   * Sets the brightness of the display.
+   * @param value {number} Floating number between 0 and 1 in which case 1 means 100% brightness and 0 means 0% brightness.
+   * @returns {Promise<any>} Returns a Promise that resolves if setting brightness was successful.
+   */
+  @Cordova()
+  setBrightness(value: number): Promise<any> {
+    return;
+  }
+
+  /**
+   * Reads the current brightness of the device display.
+   * @returns {Promise<any>} Returns a Promise that resolves with the
+   * brightness value of the device display (floating number between 0 and 1).
+   */
+  @Cordova()
+  getBrightness(): Promise<any> {
+    return;
+  }
+
+  /**
+   * Keeps the screen on. Prevents the device from setting the screen to sleep.
+   * @param {boolean} value
+   */
+  @Cordova()
+  setKeepScreenOn(value: boolean): void {
+    return;
+  }
+}