Eventually register a terminfo with ncurses upstream

Thomas Dickey, the maintainer of the ncurses project, also maintains the terminfo-db distributed with most Linux distributions. At the moment, the main TERM environment variable is xterm-256color, but not all xterm features are supported or even planned. When 1.0 releases, it would be good to leave xterm-256color as the default TERM environment, but also to maintain a separate terminfo with the ncurses project upstream. This means that as the changes in ncurses propagate down to the distros, the team can make a switchover and report the TERM as ms-terminal.

This will give the team the freedom in the long-term to add new features not implemented in xterm (for example, to support 32-bit color (i.e. an alpha channel)) or any other cool features they might dream up. Some projects like libvte and kitty have or previously had a bad relationship with the ncurses maintainer because they refused to submit their own accurate TERMINFO to the database.

No file or test is named. Start by reviewing how Windows Terminal currently selects and reports the xterm-256color TERM value, then study ncurses terminfo submission requirements and the proposed ms-terminal entry. Done means an accurate terminfo is accepted upstream and the project has a defined path for a later TERM switch.