Update 01.md (#623)

Author: michaelzetune

src/tutorials/0004-mutable-file-system/01.md

@@ -7,7 +7,7 @@
 
 [IPFS](https://ipfs.io/), or the InterPlanetary File System, is a peer-to-peer (P2P) networking protocol used to share data on the distributed web. As its full name suggests, you can think of IPFS as a file system, and it has some unique characteristics that make it ideal for safe, decentralized sharing.
 
-If you haven't yet done so, we encourage you to check out our [Content Adddressing on the Decentralized Web](https://proto.school/content-addressing/) tutorial, where you can learn all about the decentralized web and how it compares to the web you're accustomed to. There you'll learn all about content addressing, cryptographic hashing, Content Identifiers (CIDs), and sharing with peers, all of which you'll need to understand to make the most of this tutorial on IPFS.
+If you haven't yet done so, we encourage you to check out our [Content Addressing on the Decentralized Web](https://proto.school/content-addressing/) tutorial, where you can learn all about the decentralized web and how it compares to the web you're accustomed to. There you'll learn all about content addressing, cryptographic hashing, Content Identifiers (CIDs), and sharing with peers, all of which you'll need to understand to make the most of this tutorial on IPFS.
 
 ## Storing and sharing data in IPFS