Update introduction.mdx

Proofreading

docs/v3/concepts/dive-into-ton/introduction.mdx

@@ -26,7 +26,7 @@ This course introduces blockchain basics, with a special focus on practical skil
 
 - [Blockchain Basics with TON](https://stepik.org/course/201294/) ([RU version](https://stepik.org/course/202221/), [CHN version](https://stepik.org/course/200976/))
 
-## TON Blockchain Course
+## TON Blockchain Development
 
 We're proud to present the __TON Blockchain Course__, which is a comprehensive guide to the TON Blockchain. The course is designed for developers who want to learn how to create smart contracts and decentralized applications on the TON Blockchain.
 
@@ -36,23 +36,23 @@ It consists of __9 modules__ and covers the basics of the TON Blockchain, the Fu
 <Button href="https://stepik.org/course/176754/promo"
         colorType={'primary'} sizeType={'sm'}>
 
-Check TON Course
+English
 
 </Button>
 
 
 <Button href="https://stepik.org/course/201638/promo"
         colorType={'secondary'} sizeType={'sm'}>
 
-CHN
+Mandarin
 
 </Button>
 
 
 <Button href="https://stepik.org/course/201855/promo"
         colorType={'secondary'} sizeType={'sm'}>
 
-RU
+Russian
 
 </Button>