feat: add center and hr

plugins/functions.plugin.zsh

@@ -754,6 +754,44 @@ get-gh-latest-tag() {
   fi
 }
 
+center() {
+  if [[ $# -eq 0 ]]; then
+    echo_red "Usage: center <text>"
+    return 1
+  fi
+
+  print_centered "$@"
+}
+
+hr() {
+  print_centered "-" "-"
+}
+
+# from [How to center text in Bash](https://gist.github.com/TrinityCoder/911059c83e5f7a351b785921cf7ecdaa)
+function print_centered {
+   [[ $# == 0 ]] && return 1
+
+   declare -i TERM_COLS="$(tput cols)"
+   declare -i str_len="${#1}"
+   [[ $str_len -ge $TERM_COLS ]] && {
+        echo "$1";
+        return 0;
+   }
+
+   declare -i filler_len="$(( (TERM_COLS - str_len) / 2 ))"
+   [[ $# -ge 2 ]] && ch="${2:0:1}" || ch=" "
+   filler=""
+   for (( i = 0; i < filler_len; i++ )); do
+        filler="${filler}${ch}"
+   done
+
+   printf "%s%s%s" "$filler" "$1" "$filler"
+   [[ $(( (TERM_COLS - str_len) % 2 )) -ne 0 ]] && printf "%s" "${ch}"
+   printf "\n"
+
+   return 0
+}
+
 # select random element from arguments
 # NOTE always keep this function last, breaks syntax highlighting
 randarg() {