ox-ascii: Use options instead of defcustoms in code

ox-ascii: Use options instead of defcustoms in code

* lisp/ox-ascii.el (org-ascii--current-text-width,
  org-ascii--build-title, org-ascii--build-toc,
  org-ascii--list-listings, org-ascii--list-tables,
  org-ascii-template--document-title, org-ascii-inner-template,
  org-ascii-template, org-ascii-code, org-ascii-drawer,
  org-ascii-headline, org-ascii-inline-src-block,
  org-ascii-format-inlinetask-default, org-ascii-inlinetask,
  org-ascii-link, org-ascii-paragraph, org-ascii-quote-block,
  org-ascii-section, org-ascii-src-block, org-ascii-table,
  org-ascii--table-cell-width, org-ascii-table-cell,
  org-ascii-verbatim, org-ascii-verse-block,
  org-ascii-filter-headline-blank-lines,
  org-ascii-filter-paragraph-spacing): Use options instead of
  hard coded variables.