Add workflow documentation

[CameronBodine]

• [x] Move markdown docs to website
• [x] Create landing page with software overview
• [x] Add installation instructions
• [x] Add instructions for testing PING-Mapper
• [x] Add instructions for running PING-Mapper on user dataset
• [x] Show PING-Mapper exports
• [ ] Add tutorial w/ screenshots for processing sonar recordings
• [x] Provide info on collecting high quality sonar recordings
• [ ] Sonar interpretation