Add 3 new pages/sections to docs

[leewujung]

This PR partially addresses #192 and includes:

• adds a blank Quick start notebook
• adds a blank Theory notebook
• adds an Algorithmic implementation section with 2 blank notebooks algo1 and algo2
• rename input-files.md to input_files.md for consistency in terms of using "-" or ""
• exclude previous notebooks in the build
• remove homepage (index) in navbar
• add edit button