fix chezmoi segment and rename it to chezmoi_shell (#2311)

- Link to the project's homepage rather than its source code.
- Move `chezmoi_shell` next to all the other *shell indicator* segments.
- Use a shade of blue that resembes the color on chezmoi.io.
- Don't go beyond 8 colors in 8-color configs.
- Remove the segment from the *pure* config.
- Fix whitespace padding on `CHEZMOI_ICON`.
- Use the appropriate icon with all fonts (the same as `HOME`).
- Add missing `CHEZMOI_ICON` definitions for "powerline" and "ascii" font modes.
- Remove the redundant literal "chezmoi" content from the segment.
- Fix instant prompt so that the segment is shown only when `$CHEZMOI` is non-empty.

config/p10k-rainbow.zsh

@@ -45,7 +45,6 @@
     direnv                  # direnv status (https://direnv.net/)
     asdf                    # asdf version manager (https://github.com/asdf-vm/asdf)
     virtualenv              # python virtual environment (https://docs.python.org/3/library/venv.html)
-    chezmoi                 # chezmoi prompt (https://github.com/twpayne/chezmoi)
     anaconda                # conda environment (https://conda.io/)
     pyenv                   # python environment (https://github.com/pyenv/pyenv)
     goenv                   # go environment (https://github.com/syndbg/goenv)
@@ -88,6 +87,7 @@
     vim_shell               # vim shell indicator (:sh)
     midnight_commander      # midnight commander shell (https://midnight-commander.org/)
     nix_shell               # nix shell (https://nixos.org/nixos/nix-pills/developing-with-nix-shell.html)
+    chezmoi_shell           # chezmoi shell (https://www.chezmoi.io/)
     # vi_mode               # vi mode (you don't need this if you've enabled prompt_char)
     # vpn_ip                # virtual private network indicator
     # load                  # CPU load
@@ -762,13 +762,6 @@
   # Custom icon.
   # typeset -g POWERLEVEL9K_XPLR_VISUAL_IDENTIFIER_EXPANSION='⭐'
 
-  ##################[ chezmoi: chezmoi shell (https://github.com/twpayne/chezmoi) ]##################
-  # chezmoi shell color.
-  typeset -g POWERLEVEL9K_CHEZMOI_FOREGROUND=0
-  typeset -g POWERLEVEL9K_CHEZMOI_BACKGROUND=6
-  # Custom icon.
-  # typeset -g POWERLEVEL9K_CHEZMOI_VISUAL_IDENTIFIER_EXPANSION='⭐'
-
   ###########################[ vim_shell: vim shell indicator (:sh) ]###########################
   # Vim shell indicator color.
   typeset -g POWERLEVEL9K_VIM_SHELL_FOREGROUND=0
@@ -797,6 +790,13 @@
   # Custom icon.
   # typeset -g POWERLEVEL9K_NIX_SHELL_VISUAL_IDENTIFIER_EXPANSION='⭐'
 
+  ##################[ chezmoi_shell: chezmoi shell (https://www.chezmoi.io/) ]##################
+  # chezmoi shell color.
+  typeset -g POWERLEVEL9K_CHEZMOI_SHELL_FOREGROUND=0
+  typeset -g POWERLEVEL9K_CHEZMOI_SHELL_BACKGROUND=4
+  # Custom icon.
+  # typeset -g POWERLEVEL9K_CHEZMOI_SHELL_VISUAL_IDENTIFIER_EXPANSION='⭐'
+
   ##################################[ disk_usage: disk usage ]##################################
   # Colors for different levels of disk usage.
   typeset -g POWERLEVEL9K_DISK_USAGE_NORMAL_FOREGROUND=3