Reorganize dev_2ddrp/2d_PSF_code github repo to make it more useful and transparent

Current dev_2ddrp/2d_PSF_code repo is poorly organized and hard to understand for external people. The proposal is to reorganize it to be more useful and transparent. Proposed actions:

1. Remove `Data` folder containing old post-stamp images
2. Remove PIPE2D-347, PIPE2D-521 folders
3. Remove folder with presentations
4. Remove folder `Code_Repository`; move particularly useful notebook in the new folder called `Tutorials`
5. Move all *.ipynb notebook that are educational in the folder `Tutorials`
6. Update readme