Change the chain to Rococo in the parachain template Zombienet config (#5279)

Following this:
https://github.com/paritytech/polkadot-sdk-parachain-template/pull/11

---------

Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>
Co-authored-by: Bastian Köcher <git@kchr.de>

templates/parachain/README.md

@@ -59,15 +59,22 @@ docker build . -t polkadot-sdk-parachain-template
 You can grab a [released binary](https://github.com/paritytech/zombienet/releases/latest) or use an [npm version](https://www.npmjs.com/package/@zombienet/cli).
 
 This template produces a parachain node.
+You can install it in your environment by running:
+
+```sh
+cargo install --path node
+```
+
 You still need a relaychain node - you can download the `polkadot`
 (and the accompanying `polkadot-prepare-worker` and `polkadot-execute-worker`)
 binaries from [Polkadot SDK releases](https://github.com/paritytech/polkadot-sdk/releases/latest).
 
-Make sure to bring the parachain node - as well as `polkadot`, `polkadot-prepare-worker`, `polkadot-execute-worker`,
-and `zombienet` - into `PATH` like so:
+In addition to the installed parachain node, make sure to bring
+`zombienet`, `polkadot`, `polkadot-prepare-worker`, and `polkadot-execute-worker`
+into `PATH`, for example:
 
 ```sh
-export PATH="./target/release/:$PATH"
+export PATH="<path-to-binaries>:$PATH"
 ```
 
 This way, we can conveniently use them in the following steps.

templates/parachain/zombienet.toml

 [relaychain]
 default_command = "polkadot"
-chain = "dev"
+chain = "rococo-local"
 
 [[relaychain.nodes]]
 name = "alice"
 validator = true
 ws_port = 9944
 
+[[relaychain.nodes]]
+name = "bob"
+validator = true
+ws_port = 9955
+
 [[parachains]]
 id = 1000
 
 [parachains.collator]
-name = "alice"
+name = "charlie"
 ws_port = 9988
 command = "parachain-template-node"