docs(custom-tokens.mdx): remove unnecessary empty line for better rea…

…dability and consistency

docs/zkapps/writing-a-zkapp/feature-overview/custom-tokens.mdx

@@ -55,7 +55,6 @@ A token manager smart contract sets the rules around minting, burning, and sendi
 
 Use the `TokenContract` class to perform common token operations, such as minting, burning, and sending tokens. In o1js, the `TokenContract` class is your blueprint for custom token implementations.
 
-
 As shown in this [example code](https://github.com/o1-labs/o1js/blob/main/src/lib/mina/token/token-contract.unit-test.ts#L13), you inherit from the `TokenContract` class:
 
 ```ts