docs: restructure README

[saccarosium]

Hi,
this PR tries to restructure the PR to be more legible and usable by leveraging some of GF Markdown features such as admonitions and tables.

[feoh]

Hi. I can appreciate that you're trying to simplify here but I disagree with this change and feel it represents a negative departure from the current instructions.

If people use Git to clone the repo locally, they can then use git pull to update the repo from upstream as changes happen.

With your method, you've stripped that capability away which I see as a dis-service to new users.

[saccarosium]

FWIW I've just used what was already on the README. We are actually on the same page here, I will much prefer that git was the preferred, and frankly only, option for installing kickstart

[feoh]

OK thank you that makes sense. Wanna fix it and replace the unzip instructions with git clone instructions? :)

[feoh]

What does cd/dir mean? Do you mean 'cd or change directory? Or similar? Either way this isn't clear.

[saccarosium]

Same here I've reused what says now in the README. Probably would be better to write it like so:

From a terminal go to your configuration path: 
```sh
# on Linux and Mac
cd <configuration_path>
# on Windows
dir <configuration_path>
```

[feoh]

I agree. Can you please go ahead and make that fix? (Or whoever authored this PR? :)

[feoh]

I'm going to merge this as is and we can iterate more with another PR if folks are willing :)

Thanks for the contribution!