Fix wrong branch of new repository (#2064)

The new repo doesn't have the branch release-v1.0.0, I have seen people having issues with this in StackExchange:
https://substrate.stackexchange.com/questions/9839/cant-start-test-network-using-zombienet-macos
https://substrate.stackexchange.com/questions/9981/what-version-of-polkadot-relaychain-and-substrate-parachain-template-can-be-used

The options are use: 
- git clone https://github.com/paritytech/polkadot to the old repo
- Don’t do the git checkout release-v1.0.0
- Update everything to work with the version release-v1.1.0

content/md/en/docs/test/simulate-parachains.md

@@ -60,16 +60,10 @@ To prepare a working folder with the binaries for the test network:
 1. Checkout the latest release of Polkadot.
 
    Release branches use the naming convention `release-v<n.n.n>`.
-   For example, the release branch used in this tutorial is `release-v1.0.0`.
-   You can check out a more recent release branch instead of using `release-v1.0.0`.
+   For example, the release branch used in this tutorial is `release-v1.0.0` which is in master branch.
+   You can check out a more recent release branch instead of using `git checkout release-v1.1.0`.
    You can find information about recent releases and what's included in each release on the [Releases](https://github.com/paritytech/polkadot/releases) tab.
 
-   For example:
-
-   ```bash
-   git checkout release-v1.0.0
-   ```
-
 1. Compile the relay chain node by running the following command:
 
    ```bash