Update the config reference

Author: alcuadrado

src/content/docs/docs/reference/configuration.mdx

@@ -153,7 +153,7 @@ The following options are specific to simulated networks:
 - `coinbase`: The address used as coinbase in new blocks. Default value: `"0xc014ba5ec014ba5ec014ba5ec014ba5ec014ba5e"`.
 - `forking`: An object that describes the forking configuration and can have the following fields:
   - `url`: a URL that points to a JSON-RPC node with state that you want to fork off. There's no default value for this field. It must be provided for the fork to work.
-  - `blockNumber`: an optional number to pin which block to fork from. If no value is provided, the latest block is used.
+  - `blockNumber`: an optional number or bigint to pin which block to fork from. If no value is provided, the latest block is used.
   - `enabled`: an optional boolean to switch on or off the fork functionality. Default value: `true` if `url` is set, `false` otherwise.
 - `hardfork`: This setting changes how Hardhat Network works, to mimic Ethereum's mainnet at a given hardfork. It must be one of `"byzantium"`, `"constantinople"`, `"petersburg"`, `"istanbul"`, `"muirGlacier"`, `"berlin"`, `"london"`, `"arrowGlacier"`, `"grayGlacier"`, `"merge"`, `"shanghai"`, `"cancun"`, `"prague"`, and `"osaka"`. Default value: `"osaka"`.
 - `initialBaseFeePerGas`: The `baseFeePerGas` of the first block. Note that when forking a remote network, the "first block" is the one immediately after the block you forked from. This field must not be present if `hardfork` is not `"london"` or a later one. Default value: `"1000000000"` if not forking. When forking a remote network, if the remote network uses EIP-1559, the first local block will use the right baseFeePerGas according to the EIP, otherwise `"10000000000"` is used.