Minor edits to the readme

Initial release after moving the codebase to GitHub. Major changes include:

• Added generative example data that mimics real ultrasound SWEI data
• Added four example scripts showcasing package functionality
• Added helper scripts to create masks
• Changed CalcTheta to log-uniform sampling
• Changed argument order of some functions to be more consistent
• Fixed radon_ones normalization bug
• Improved PlotRadon