Add agnoster.zsh-theme

themes/agnoster.zsh-theme

+# Theme by [agnoster](https://github.com/agnoster)
+# See https://gist.github.com/3712874
+
+ZSH_THEME_GIT_PROMPT_DIRTY='±'
+
+function _git_prompt_info() {
+  ref=$(git symbolic-ref HEAD 2> /dev/null) || ref="➦ $(git show-ref --head -s --abbrev |head -n1 2> /dev/null)"
+  echo "${ref/refs\/heads\//⭠ }$(parse_git_dirty)"
+}
+
+function _git_info() {
+  if $(git rev-parse --is-inside-work-tree >/dev/null 2>&1); then
+    local BG_COLOR=green
+    if [[ -n $(parse_git_dirty) ]]; then
+      BG_COLOR=yellow
+    fi
+    echo "%{%K{$BG_COLOR}%}⮀%{%F{black}%} $(_git_prompt_info) %{%F{$BG_COLOR}%K{blue}%}⮀"
+  else
+    echo "%{%K{blue}%}⮀"
+  fi
+}
+
+PROMPT_HOST='%{%b%F{gray}%K{black}%} %(?.%{%F{green}%}✔.%{%F{red}%}✘)%{%F{gray}%} %m %{%F{black}%}'
+PROMPT_DIR='%{%F{white}%} %1~ '
+PROMPT_SU='%(!.%{%k%F{blue}%K{black}%}⮀%{%F{yellow}%} ⚡ %{%k%F{black}%}.%{%k%F{blue}%})⮀%{%f%k%b%}'
+
+PROMPT='%{%f%b%k%}
+$PROMPT_HOST$(_git_info)$PROMPT_DIR$PROMPT_SU '