Make the readme quickstart more user-friendly (!1684) · Merge requests · OpenHW Group / backup-20241120 / cva6

Created by: valentinThomazic

Made the Quickstart section of the README more straightforward and enticing people to use the scripts to build the toolchain and the tools, to avoid potential issues like these ones : https://github.com/openhwgroup/cva6/issues/1631 https://github.com/openhwgroup/cva6/issues/1410 https://github.com/openhwgroup/cva6/issues/1489

Removed the table of content since it is now integrated into Github README viewer.

Moved the contributing and publication section at the bottom.

Removed references to some docs images that are not present in the repo anymore.

Make the readme quickstart more user-friendly