[OSCI][Doc]Updated EUI doc site links to OUI doc site (#5293) (#5308)

* [OSCI][Doc]Updated EUI doc site links to OUI doc site
* [OSCI][Doc]Updated PR details in CHANGELOG

---------

Signed-off-by: Vijay Vavdiya <vijayvavdiya@gmail.com>
Co-authored-by: Ashwin P Chandran <ashwinpc@amazon.com>
(cherry picked from commit 534b2d0)
Signed-off-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: Josh Romero <rmerqg@amazon.com>

Author: 4 people

DEVELOPER_GUIDE.md

@@ -454,7 +454,7 @@ You can also use this service outside of React.
 
 When writing a new component, create a sibling SASS file of the same name and import directly into the **top** of the JS/TS component file. Doing so ensures the styles are never separated or lost on import and allows for better modularization (smaller individual plugin asset footprint).
 
-All SASS (.scss) files will automatically build with the [EUI](https://elastic.github.io/eui/#/guidelines/sass) & OpenSearch Dashboards invisibles (SASS variables, mixins, functions) from the [`globals_[theme].scss` file](src/core/public/core_app/styles/_globals_v7light.scss).
+All SASS (.scss) files will automatically build with the [OUI](https://oui.opensearch.org/#/guidelines/sass) & OpenSearch Dashboards invisibles (SASS variables, mixins, functions) from the [`globals_[theme].scss` file](src/core/public/core_app/styles/_globals_v7light.scss).
 
 While the styles for this component will only be loaded if the component exists on the page,
 the styles **will** be global and so it is recommended to use a three letter prefix on your

src/plugins/home/server/services/tutorials/lib/tutorial_schema.ts

@@ -124,7 +124,7 @@ export const tutorialSchema = {
   moduleName: Joi.string(),
   isBeta: Joi.boolean().default(false),
   shortDescription: Joi.string().required(),
-  euiIconType: Joi.string(), // EUI icon type string, one of https://elastic.github.io/eui/#/icons
+  euiIconType: Joi.string(), // OUI icon type string, one of https://oui.opensearch.org/#/display/icons
   longDescription: Joi.string().required(),
   completionTimeMinutes: Joi.number().integer(),
   previewImagePath: Joi.string(),

src/plugins/home/server/services/tutorials/lib/tutorials_registry_types.ts

@@ -95,7 +95,7 @@ export interface TutorialSchema {
   moduleName?: string;
   isBeta?: boolean;
   shortDescription: string;
-  euiIconType?: IconType; // EUI icon type string, one of https://elastic.github.io/eui/#/display/icons;
+  euiIconType?: IconType; // OUI icon type string, one of https://oui.opensearch.org/#/display/icons;
   longDescription: string;
   completionTimeMinutes?: number;
   previewImagePath?: string;

src/plugins/opensearch_dashboards_legacy/public/notify/toasts/TOAST_NOTIFICATIONS.md

@@ -1,6 +1,6 @@
 # Toast notifications
 
-Use this service to surface toasts in the bottom-right corner of the screen. After a brief delay, they'll disappear. They're useful for notifying the user of state changes. See [the EUI docs](https://elastic.github.io/eui/) for more information on toasts and their role within the UI.
+Use this service to surface toasts in the bottom-right corner of the screen. After a brief delay, they'll disappear. They're useful for notifying the user of state changes. See [the OUI docs](https://oui.opensearch.org/) for more information on toasts and their role within the UI.
 
 ## Importing the module
 
@@ -57,7 +57,7 @@ toastNotifications.remove(toast);
 
 ### Configuration options
 
-If you want to configure the toast further you can provide an object instead of a string. The properties of this object correspond to the `propTypes` accepted by the `EuiToast` component. Refer to [the EUI docs](https://elastic.github.io/eui/) for info on these `propTypes`.
+If you want to configure the toast further you can provide an object instead of a string. The properties of this object correspond to the `propTypes` accepted by the `OuiToast` component. Refer to [the OUI docs](https://oui.opensearch.org/) for info on these `propTypes`.
 
 ```js
 toastNotifications.add({