Multiple polishes with R 4.0

• Multiple updates and changes accompany with the recent ctmmweb paper. Including a new guide page for different workflow modes, many updates on help documents.
• Changed the recomanded installation method to remotes::install_github.
• Tested with R 4.0 and the 0.5.10 version of ctmm.
• Fixed the bug with collecting diganostic info in app, which was very tricky with manipulating connections.
• Updated the windows installer to R 4.0.2 and remotes installation method.