Apply suggestions from code review

Co-authored-by: Radha <[email protected]>

Author: kianenigma

content/md/en/docs/polkadot-sdk/index.md

@@ -14,14 +14,14 @@ Parity Technologies started moving 3 repositories of
 [`substrate`](https://github.com/paritytech/substrate),
 [`polkadot`](https://github.com/paritytech/polkadot), and
 [`cumulus`](https://github.com/paritytech/cumulus), formerly independent in development and
-branding, under one mew mono-repo called
+branding, under one new mono-repo called
 [`polkadot-sdk`](https://github.com/paritytech/polkadot-sdk). Consequently, the [runtimes of the
-Polkadot and Kusama relay chains, and their system chain](https://github.com/polkadot-fellows/runtimes) were moved to be maintained by the [Polkadot fellowship](polkadot-fellows.github.io/dashboard/).
+Polkadot and Kusama relay chains, and their system chains](https://github.com/polkadot-fellows/runtimes) were moved to be maintained by the [Polkadot fellowship](polkadot-fellows.github.io/dashboard/).
 
-This transition gave birth to a new vision in which these tools are seen from lense of being part of `polkadot-sdk`, while still being independently useful.
+This transition gave birth to a new vision in which these tools are seen from the lens of being part of `polkadot-sdk` while still being independently useful.
 
-Most impacted in this transition is **Substrate**, and part of this impact is gradual deprecation of
-this website. The content in this website is no longer maintained, and will be gradually moved to a
+Most impacted in this transition is **Substrate**, and part of this impact is the gradual deprecation of
+this website. The content on this website is no longer maintained and will be gradually moved to a
 new home. Consider the [resources below](#alternative-resources) as primary sources of information.
 
 > You may still access the old content of this website in the navbar, but be aware of the fact that some content might not be up to date.
@@ -32,8 +32,8 @@ Note that **this does not impact the development of Substrate as a framework**.
 
 Below, you can find a number of replacement resources to learn more about Polkadot SDK:
 
-- [Polkadot Wiki](https://wiki.polkadot.network/)
+- [Polkadot Wiki](https://wiki.polkadot.network/docs/build-guide)
 - [Polkadot Developers](https://github.com/polkadot-developers/)
-- [Polkadot Blockchain Academy](https://academy.polkadot.network/)
-- [Polkadot Ecosystem Documentation by Papermoon](https://wiki.polkadot.network/)
-- [Polkadot SDK Rust Docs](https://wiki.polkadot.network/)
+- [Polkadot Blockchain Academy](https://polkadot.com/blockchain-academy)
+- Polkadot Ecosystem Documentation by Papermoon (Work in progress)
+- [Polkadot SDK Rust Docs](https://paritytech.github.io/polkadot-sdk/master/polkadot_sdk_docs/index.html)