Updated readme file with better design, less text (#1265)

- Re-structure - changed the way the document is structured (table of content), including changing titles names
- Redesigned the header - with better look and feel, with as much information in the header.
- Removed tutorials from the tutorials section in the readme - will add some back after re-structuring the tutorials.
- Added visuals to the page for better look and feel, and to better explain the product.
- improved the quantization flow table and added 4 tutorials to it.
- Re-ordered the Resources section, making it clear that API is per quantization method
- Hidden (collapsed) the supported version table. users can open it on demand
- Results - removed text, still requires updating the numbers, add mixed precision and the update graph
- Troubleshooting and community - added community to this section.
- Updated the license section with text and a badge