remove MULTIBYTE requirement from the configuration wizard (#2397)

README.md

@@ -1696,10 +1696,15 @@ and make sure that `TERM` environment variable is set correctly. Verify with
 If there is no UTF-8 locale on the system, configuration wizard won't offer prompt styles that use
 Unicode characters. *Fix*: Install a UTF-8 locale. Verify with `locale -a`.
 
-When a UTF-8 locale is available, the first few questions asked by the configuration wizard assess
-capabilities of the terminal font. If your answers indicate that some glyphs don't render correctly,
-configuration wizard won't offer prompt styles that use them. *Fix*: Restart your terminal and
-install [the recommended font](#meslo-nerd-font-patched-for-powerlevel10k). Verify by running
+Another case in which configuration wizard may not offer Unicode prompt styles is when the
+`MULTIBYTE` shell option is disabled. *Fix*: Enable the `MULTIBYTE` option, or rather don't disable
+it (this option is enabled in Zsh by default). Verify with `print -r -- ${options[MULTIBYTE]}`.
+
+When `MULTIBYTE` is enabled and a UTF-8 locale is available, the first few questions asked by the
+configuration wizard assess capabilities of the terminal font. If your answers indicate that some
+glyphs don't render correctly, configuration wizard won't offer prompt styles that use them. *Fix*:
+Restart your terminal and install
+[the recommended font](#meslo-nerd-font-patched-for-powerlevel10k). Verify by running
 `p10k configure` and checking that all glyphs render correctly.
 
 ### Cannot install the recommended font

internal/configure.zsh

@@ -18,7 +18,6 @@ function _p9k_can_configure() {
   typeset -g __p9k_cfg_path=${__p9k_cfg_path_o:A}
   typeset -g __p9k_cfg_path_u=${${${(q)__p9k_cfg_path_o}/#(#b)${(q)HOME}(|\/*)/'~'$match[1]}//\%/%%}
   {
-    [[ -o multibyte ]]         || { $0_error "multibyte option is not set";      return 1 }
     [[ -e $__p9k_zd ]]         || { $0_error "$__p9k_zd_u does not exist";       return 1 }
     [[ -d $__p9k_zd ]]         || { $0_error "$__p9k_zd_u is not a directory";   return 1 }
     [[ ! -d $__p9k_cfg_path ]] || { $0_error "$__p9k_cfg_path_u is a directory"; return 1 }

internal/wizard.zsh

@@ -2107,7 +2107,7 @@ while true; do
 
   unset pure_use_rprompt
 
-  if [[ $TERM != (dumb|linux) && $langinfo[CODESET] == (utf|UTF)(-|)8 ]]; then
+  if [[ -o multibyte && $TERM != (dumb|linux) && $langinfo[CODESET] == (utf|UTF)(-|)8 ]]; then
     ask_font || continue
     ask_diamond || continue
     if [[ $AWESOME_GLYPHS_LOADED == 1 ]]; then