VectorChat $CHAT: 3/13-3/20 Dev Log

- Added multi-line inputs in chat window
- Added rendering of markdown and code
- Added infrastructure for setting usernames and eventually creating entire profile customization page
- Added support for converting uploaded images for characters and profile pictures to both png and jpeg
- Better formatting of character outputs like separation into logical paragraphs
- Implemented support of transparent images for sharing
- Fixed search functionality, and improved search to use searching algorithm matching entire substrings rather than only prefixes
- Created on-boarding documents & updated internal documentation for new developers