Update README (update testnet version, link to the bootnode list and sha256sum of genesis)

Signed-off-by: Doctor K <doctor_whoami@ghostchain.io>

README.md

@@ -320,7 +320,7 @@ Only `port 30333` should be opened.
 
 Press _CTRL+C_ to stop the node.
 
-# Launching GHOST TestNet 2.0
+# Launching GHOST TestNet 3.1
 
 Switch to main GIT branch:
 ```bash
@@ -491,7 +491,7 @@ Official **Boot Node** addresses:
 /dns/bootnode70.chain.ghostchain.io/tcp/30333/p2p/12D3KooWP3h5dSdqcpvsCr7fp1jyfqDj291QDZ68a4gY6VQ8T1nW
 ```
 
-A full list of available **Boot Nodes** can be found on [the guide page](https://blog.ghostchain.io/launching-ghost-testnet-2-0/#Boot_Node).
+A full list of available **Boot Nodes** can be found on [the guide page](https://blog.ghostchain.io/launching-ghost-testnet-3-0/#Boot_Node).
 
 ![images/img_33.png](images/img_33.png)