(DOCSP-26989): @realm/reactify 'Index a Property' (#2451)

## Pull Request Info

### Jira

- https://jira.mongodb.org/browse/DOCSP-26989

### Staged Changes

- [Index a
Property](https://docs-mongodbcom-staging.corp.mongodb.com/realm/docsworker-xlarge/DOCSP-26989/sdk/react-native/realm-database/schemas/index/)

### Reminder Checklist

If your PR modifies the docs, you might need to also update some
corresponding
pages. Check if completed or N/A.

- [x] Create Jira ticket for corresponding docs-app-services update(s),
if any
- [x] Checked/updated Admin API
- [x] Checked/updated CLI reference

### Review Guidelines


[REVIEWING.md](https://github.com/mongodb/docs-realm/blob/master/REVIEWING.md)

Author: davidhou17

examples/react-native/__tests__/js/models/Book.js

@@ -0,0 +1,14 @@
+import Realm from 'realm';
+
+// :snippet-start: js-book-schema
+class Book extends Realm.Object {
+  static schema = {
+    name: 'Book',
+    properties: {
+      name: { type: 'string', indexed: true },
+      price: 'int?',
+    },
+  };
+}
+// :snippet-end:
+export default Book;

examples/react-native/__tests__/ts/models/Book.ts

@@ -0,0 +1,18 @@
+import Realm from 'realm';
+
+// TODO: Replace `static schema` with TS-first models + realm-babel-plugin (https://www.npmjs.com/package/@realm/babel-plugin) approach once realm-babel-plugin version 0.1.2 releases with bug fixes
+// :snippet-start: ts-book-schema
+class Book extends Realm.Object<Book> {
+  name!: string;
+  price?: number;
+
+  static schema = {
+    name: 'Book',
+    properties: {
+      name: { type: 'string', indexed: true },
+      price: 'int?',
+    },
+  };
+}  
+// :snippet-end:
+export default Book;

source/examples/generated/react-native/js/Book.snippet.js-book-schema.js

@@ -0,0 +1,9 @@
+class Book extends Realm.Object {
+  static schema = {
+    name: 'Book',
+    properties: {
+      name: { type: 'string', indexed: true },
+      price: 'int?',
+    },
+  };
+}

source/examples/generated/react-native/ts/Book.snippet.ts-book-schema.ts

@@ -0,0 +1,12 @@
+class Book extends Realm.Object<Book> {
+  name!: string;
+  price?: number;
+
+  static schema = {
+    name: 'Book',
+    properties: {
+      name: { type: 'string', indexed: true },
+      price: 'int?',
+    },
+  };
+}  

source/sdk/node/examples/define-a-realm-object-model.txt

@@ -159,7 +159,7 @@ properties. To define an index for a given property, set ``indexed`` to
 .. note::
 
    An **index** significantly increases the speed of certain read operations at
-   the cost of  slightly slower write times and additional storage and memory
+   the cost of slightly slower write times and additional storage and memory
    overhead. Realm Database stores indexes on disk, which makes your realm files
    larger. Each index entry is a minimum of 12 bytes. The ordering of the index
    entries supports efficient equality matches and range-based query operations. 

source/sdk/react-native/realm-database/schemas/index.txt

@@ -15,26 +15,43 @@ Index a Property - React Native SDK
 Overview
 --------
 
-Realm supports indexing for string, integer, boolean, ``Date``, ``UUID``, and ``ObjectId``
-properties. To define an index for a given property, set ``indexed`` to
-``true``.
+If you frequently run :ref:`read operations <react-native-read-operations>` 
+based on a specific property, you can index the property to optimize 
+performance. Realm supports indexing for string, integer, boolean, ``Date``, 
+``UUID``, and ``ObjectId`` properties. 
 
 .. note::
 
    An **index** significantly increases the speed of certain read operations at
-   the cost of  slightly slower write times and additional storage and memory
+   the cost of slightly slower write times and additional storage and memory
    overhead. Realm Database stores indexes on disk, which makes your realm files
    larger. Each index entry is a minimum of 12 bytes. The ordering of the index
    entries supports efficient equality matches and range-based query operations. 
-   
-   It's best to only add indexes when optimizing the read performance for
-   specific situations.
-
-.. example::
-   
-   The following ``Book`` object schema defines an index on the ``name``
-   property.
+
+Usage
+-----
+To index a given property, set the property's ``indexed`` field to ``true``.
+
+Example
+~~~~~~~
+
+In the following example of a ``Book`` class, we define an index on the ``name``
+property.
 
-   .. literalinclude:: /examples/Schemas/Indexed.js
-      :language: javascript
-      :emphasize-lines: 4
+.. tabs-realm-languages::
+
+   .. tab::
+      :tabid: typescript
+
+      .. literalinclude:: /examples/generated/react-native/ts/Book.snippet.ts-book-schema.ts
+         :language: typescript
+         :emphasize-lines: 8
+         :linenos:
+
+   .. tab::
+      :tabid: javascript
+
+      .. literalinclude:: /examples/generated/react-native/js/Book.snippet.js-book-schema.js
+         :language: javascript
+         :emphasize-lines: 5
+         :linenos: