Fixed typo in link (polkadot-developers#1953)

Co-authored-by: Kian Paimani <[email protected]>

content/md/en/docs/quick-start/modify-the-runtime.md

@@ -4,7 +4,7 @@ description: Make simple changes to the default node template to create a custom
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-In [Explore the code](/quick-start/explore the-code/), you learned about the manifest files and Rust modules that make up the default node template.
+In [Explore the code](/quick-start/explore-the-code/), you learned about the manifest files and Rust modules that make up the default node template.
 Now that you have a general idea of what the runtime source code looks like, let's look at how easy it is for you to make a few simple changes to customize the runtime.
 
 For this simple demonstration, you are going to do the following:
@@ -292,4 +292,4 @@ To verify your changes:
 After verifying the changes, you know that you have a customized version of the node template running and have successfully upgraded your local node to use your modified runtime.
 
 That's quite an achievement, but there's a lot more you can do. 
-To dig deeper into concepts and core components, review topics in the [Learn](/learn/) section or start building on what you've learned so far by exploring topics in the [Build](/build/) section.
+To dig deeper into concepts and core components, review topics in the [Learn](/learn/) section or start building on what you've learned so far by exploring topics in the [Build](/build/) section.