Support true colors and italics in tmux and vim.

tmux.conf

@@ -21,8 +21,10 @@ bind h split-window -v
 # Enable vi-like key bindings for navigating around buffers.
 set-window-option -g mode-keys vi
 
-# Force tmux to consider the enclosing terminal true-color-capable.
-set -ga terminal-overrides ',screen-256color:Tc'
+# Enable italics and true color.
+# See https://herrbischoff.com/2020/08/how-to-enable-italics-in-tmux/.
+set -g default-terminal "tmux"
+set-option -sa terminal-overrides ',xterm*:Tc'
 
 # List of plugins
 set -g @plugin 'tmux-plugins/tpm'