flow evm is really flow previewnet (#642)

* flow evm is really flow previewnet

* revert gateway name

* update variable name for clarity

docs/evm/build/guides/deploy-contract/using-hardhat.md

@@ -105,7 +105,7 @@ Deploying:
 3. Create a `deploy.ts` file in `scripts` directory.
 4. Paste in the following TypeScript code.
 
-```typeScript
+```javascript
 import { ethers } from "hardhat";
 
 async function main() {
@@ -141,7 +141,7 @@ HelloWorld address: 0x3Fe94f43Fb5CdB8268A801f274521a07F7b99dfb
 
 Now, we want to get the greeting from the deployed `HelloWorld` smart contract.
 
-```TypeScript
+```javascript
 import { ethers } from "hardhat";
 import HelloWorldABI from "../artifacts/contracts/HelloWorld.sol/HelloWorld.json";
 
@@ -176,7 +176,7 @@ The greeting is: Hello, World!
 
 Next, we'll add a script to update the greeting and log it.
 
-```TypeScript
+```javascript
 import { ethers } from "hardhat";
 import HelloWorldABI from "../artifacts/contracts/HelloWorld.sol/HelloWorld.json";
 

src/components/addNetworkButton.tsx

@@ -7,7 +7,7 @@ import {
 export const AddNetworkButton = () => {
   const hasEthereum = window?.ethereum !== undefined;
 
-  const addFlowEVM = async () => {
+  const addFlowPreviewnet = async () => {
     try {
       // Define your network details here
       await window?.ethereum?.request({
@@ -30,13 +30,13 @@ export const AddNetworkButton = () => {
         ],
       });
     } catch (error) {
-      console.error('Could not add Flow EVM', error);
+      console.error('Could not add Flow Previewnet', error);
     }
   };
 
   // eslint-disable-next-line @typescript-eslint/no-misused-promises
   return hasEthereum ? (
-    <Button className="my-5 " variant="secondary" onClick={addFlowEVM}>
+    <Button className="my-5 " variant="secondary" onClick={addFlowPreviewnet}>
       Add Flow Previewnet Network
     </Button>
   ) : (