Fix extra period

Author: TucksonDev

README.md

@@ -49,7 +49,7 @@ yarn install
 
 As mentioned above, these tutorials use the [Arbitrum SDK](https://github.com/OffchainLabs/arbitrum-sdk), which loads the regular Arbitrum chains by default (Arbitrum One, Arbitrum Nova and Arbitrum Sepolia). You can use these tutorials against any other Arbitrum chain (including Orbit chains), by loading it to the Arbitrum SDK.
 
-To do that, fill the information of your chain in the [`customNetwork.json`](./customNetwork.json) file., which is automatically loaded in all tutorials.
+To do that, fill the information of your chain in the [`customNetwork.json`](./customNetwork.json) file, which is automatically loaded in all tutorials.
 
 To obtain the information of a specific chain, you can use the method [`prepareArbitrumNetwork`](https://github.com/OffchainLabs/arbitrum-orbit-sdk/blob/main/src/utils/registerNewNetwork.ts#L18) of the Orbit SDK.