Provide two new modalities for CLI

[tahsinkose]

Hey there,

I initially thank you for this fork. It allowed me to monitor my CPU flawlessly. This PR involves the changes I made locally to make use of the CLI program through Conky. I'm not a Conky expert, so I was not really sure whether the current version of CLI is directly usable with some Lua scripting. Instead of that, I went ahead with providing the following two options:

1. --output-once. This simple flag allows the CLI program to finish immediately after printing the latest information about the CPU. I'm using it to update my Conky widget, however, it can be used by any such monitoring application.
2. --refresh-in-place. This is also a simple flag. It pops up an ncurses windows and flushes the information block. This might be useful for those who want to embed the terminal output into widgets. It requires libncurses5-dev to be installed as I added to README.

This diff allowed me to monitor my 8-core Ryzen 7 5800H CPU in a very neat way 🙂

[Ta180m]

Thanks for the PR! It looks great.