minor Improvements to the tutorial

[stefanopepe]

We are already updating our official docs, you can already update your tutorial with this key info:

• the command make release will build both the docker image and the binary file
• the command cargo build -p neard --release will build only the binary, and should save some time (as it doesn't have to build the container too)

Please experiment it yourself, and decide if it's worth to mention in this very good tutorial :)

[stefanopepe]

I would also suggest cloning the release in a folder that identifies the build hash, for example:

nearcore-57bde24
nearcore-e6da44c7
nearcore-2d02b33
nearcore-aac1460

The command is easy, you just have to specify the folder as follows:
git clone -b beta https://github.com/nearprotocol/nearcore.git nearcore-a4f57f91

[navneetlakra]

Thanks for the feedback, it's great. I will update the document shortly.

[navneetlakra]

@jimmy3dita I have updated the document as per review comments. Can you please validate?