os/tty: mention true-color and italics in readme

modules/os/tty/README.org

@@ -53,7 +53,55 @@ need
     to work.
 
 * Configuration
-# How to configure this module, including common problems and how to address them.
+** True-color and italic support
+(credit goes to [[https://github.com/syl20bnr/spacemacs/wiki/Terminal][the spacemacs wiki]] for this information)
+
+Create a =xterm-24bit.terminfo= file with the following contents:
+
+#+BEGIN_SRC text
+xterm-24bit|xterm with 24-bit direct color mode,
+   use=xterm-256color,
+   sitm=\E[3m,
+   ritm=\E[23m,
+   setb24=\E[48;2;%p1%{65536}%/%d;%p1%{256}%/%{255}%&%d;%p1%{255}%&%dm,
+   setf24=\E[38;2;%p1%{65536}%/%d;%p1%{256}%/%{255}%&%d;%p1%{255}%&%dm,
+#+END_SRC
+
+#+begin_quote
+WARNING: Make sure you have a newline at end of file otherwise you will get
+errors!
+#+end_quote
+
+Execute the following command on the command line:
+#+BEGIN_SRC sh
+tic -x -o ~/.terminfo xterm-24bit.terminfo
+#+END_SRC
+
+Now set your ~$TERM~ variable to ~xterm-24bit~:
+#+BEGIN_SRC sh
+export TERM=xterm-24bit
+#+END_SRC
+
+SSH might break if your remote machine does not have the same setup, you can
+work around this with the following alias.
+#+BEGIN_SRC sh
+alias ssh="TERM=xterm-256color ssh"
+#+END_SRC
+
+If you use tmux, you need to make sure you installed a version with truecolor
+support, then add the following lines to your `.tmux.conf`:
+#+BEGIN_SRC conf
+set -g default-terminal "xterm-24bit"
+set -g terminal-overrides ',xterm-24bit:Tc'
+#+END_SRC
+
+Also, make sure you have utf8 language variables if you want all characters to
+display correctly. For example:
+#+BEGIN_SRC bash
+export LC_ALL=en_US.UTF-8
+export LANG=en_US.UTF-8
+export LANGUAGE=en_US.UTF-8
+#+END_SRC
 
 * Troubleshooting
 # Common issues and their solution, or places to look for help.