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

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
@@ -437,9 +437,8 @@ sha256sum /etc/ghost/casper.json
 
 You should see:
 ```
-5aeb6fd5b9b14bdbc1a61600655b5217ded7c1b7cb05bd32929354e88935ae97
+ad653233c978bfd00c5e4525b17628632bc4319c5f5f4b4dcc2f050ef3c3d145
 ```
-![images/img_29.png](images/img_29.png)
 
 Create running `ghost-node` service that starts on system boot using `--unit-file` flag.
 And we must set up the `ghost-node` launch command by setting arguments using
@@ -492,7 +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-3-1/#Boot_Node).
 
 ![images/img_33.png](images/img_33.png)
 
@@ -508,7 +507,7 @@ Type `y` and press _Enter_ for create dedicated user for running `ghost-node`:
 
 ![images/img_36.png](images/img_36.png)
 
-**DO NOT start and enable** `ghost-node.service` press _Enter_:
+**DO NOT start and DO NOT enable** `ghost-node.service` (press _Enter_):
 
 ![images/img_37.png](images/img_37.png)