docs: mention fetch removal in version migration instructions

Author: penovicp

www/docs/guides/migrate.md

@@ -2,104 +2,25 @@
 sidebar_position: 101
 ---
 
-# Migrate from v5 to v6
+# Migrate from v6 to v7
 
-This document only covers the features present in v5 which have changed in some significant way in v6.
+This document only covers the features present in v6 which have changed in some significant way in v7.
 
 If you encounter any missing changes, please let us know and we will update this guide.
 
-## Transaction receipt
+## Fetch dependencies
 
-When sending a transaction, the receipt type has changed.
-In V5, it's an object that can have varied definitions, depending on the status and the type of transaction.
-In V6, this object is in `TxR.value`, and several helpers are available (`.statusReceipt`, `isSuccess()`, `isRejected()`, `isReverted()`, `.isError()`, `match`, ...)
+`isomorphic-fetch` and `fetch-cookie` have been removed as dependencies.
 
-```typescript
-const response = await ethContract.approve(swapContractAddress, cairo.uint256(100000));
-const transactionReceipt = await provider.waitForTransaction(response.transaction_hash);
-
-// v5 : transactionReceipt is just an object
-{
-type: 'INVOKE',
-  transaction_hash: '0x5286217518c621581ac85505a99ffe182ce1114abaa8fce8b418d2b27c3c04c',
-  actual_fee: { unit: 'WEI', amount: '0x1c1902fe99800' },
-  messages_sent: [],
-  execution_status: 'SUCCEEDED',
-  finality_status: 'ACCEPTED_ON_L2',
-  // ...
-}
-// v6 : transactionReceipt is an object + helpers
-const receipt = transactionReceipt.value;
-const status: boolean = transactionReceipt.isSuccess();
-
-```
-
-> See this [guide](./interact.md#transaction-receipt-response)
-
-## Long strings
-
-Starknet.js v6 is compatible with Cairo v2.4.0. It means that long strings (>31 characters) are automatically handled and converted to the Cairo `ByteArray` type.
-This means that the approach to convert a long string to an array of felts (for Cairo 0 contracts for example) has changed:
+For users who might require the features of either library, a `baseFetch` override parameter has been enabled for the `RpcProvider` and `RpcChannel` classes, including classes that inherit from them such as `Account` and `WalletAccount`.
 
 ```typescript
-// v5
-const feltArray: BigNumberish[] = CallData.compile(
-  'http://addressOfMyERC721pictures/storage/image1.jpg'
-);
+import makeFetchCookie from 'fetch-cookie';
+import isomorphicFetch from 'isomorphic-fetch';
 
-// v6
-const feltArray: BigNumberish[] = CallData.compile(
-  shortString.splitLongString('http://addressOfMyERC721pictures/storage/image1.jpg')
-);
+const provider = new RpcProvider({
+  baseFetch: makeFetchCookie(isomorphicFetch),
+});
 ```
 
-## Fees
-
-All functions related to gas price and fee estimation have changed output types.
-
-For example, if you read the content of a block with v5 the ETH gas price was a top level property, with v6 the same information is nested a level deeper:
-
-```typescript
-const resp: GetBlockResponse = await myProvider.getBlock('latest');
-
-// v5
-const gasPrice = resp.gas_price;
-
-// v6
-const gasPrice = resp.l1_gas_price.price_in_wei;
-```
-
-Another example is `estimateDeclareFee()` where the response object has changed:
-
-```typescript
-const fee = await account0.estimateDeclareFee({ contract: compiledContract });
-
-// v5 response
-fee = {
-  overall_fee: 247700000000000n,
-  gas_consumed: 2477n,
-  gas_price: 100000000000n,
-  suggestedMaxFee: 371550000000000n,
-};
-
-// v6 response
-fee = {
-  overall_fee: 247700000000000n,
-  gas_consumed: 2477n,
-  gas_price: 100000000000n,
-  unit: undefined,
-  suggestedMaxFee: 371550000000000n,
-  resourceBounds: {
-    l2_gas: { max_amount: '0x0', max_price_per_unit: '0x0' },
-    l1_gas: { max_amount: '0xaa4', max_price_per_unit: '0x22ecb25c00' },
-  },
-};
-```
-
-You have to adapt your code to all these new entries.
-In general, pay attention to the result types of methods that return a response from an RPC node.
-
-<br/>
-<hr/>
-
-For the old v4 to v5 migration instructions check [here](./migrate_v4).
+## ...