feat(afowler): add mercurial support

Closes #5992

themes/afowler.zsh-theme

@@ -1,5 +1,10 @@
-PROMPT='%m %B%F{blue}:: %b%F{green}%3~ $(git_prompt_info)%B%(!.%F{red}.%F{blue})»%f%b '
+PROMPT='%m %B%F{blue}:: %b%F{green}%3~ $(hg_prompt_info)$(git_prompt_info)%B%(!.%F{red}.%F{blue})»%f%b '
 RPS1='%(?..%F{red}%? ↵%f)'
 
 ZSH_THEME_GIT_PROMPT_PREFIX="%{$fg[yellow]%}‹"
 ZSH_THEME_GIT_PROMPT_SUFFIX="› %{$reset_color%}"
+
+ZSH_THEME_HG_PROMPT_PREFIX="%{$fg[magenta]%}hg:‹%{$fg[yellow]%}"
+ZSH_THEME_HG_PROMPT_SUFFIX="%{$fg[magenta]%}› %{$reset_color%}"
+ZSH_THEME_HG_PROMPT_DIRTY=" %{$fg[red]%}✗"
+ZSH_THEME_HG_PROMPT_CLEAN=""