removed apostrophe

Author: eabdelmoneim

apps/portal/src/app/nebula/page.mdx

@@ -47,7 +47,7 @@ Nebula is currently available in Alpha. [Join the waitlist.](https://thirdweb.co
 ### Understanding Smart Contracts
 - "What ERC standards are implemented by contract address 0x59325733eb952a92e069C87F0A6168b29E80627f on Ethereum?"
 - "What functions can I use to mint more of my contract's NFTs?"
-- "What is the total supply of NFT's for my contract?"
+- "What is the total supply of NFTs for my contract?"
 
 ### Interacting with wallets
 - "How much ETH is in my wallet?"