Updates of "The {pIqaD} Playground".

* Updated CSS to the Klingonska Akademien design.

* Moved: `piqad/play.cgi` -> `writing/play/`.

* Updated all links to "The {pIqaD} Playground" on website to point to
  the new location.

* Split off help text into separate HTML file
  (`writing/play/help.html`).
Corrected faulty link.

* "{pIqaD}, And How to Read It" contained an erroneous link which
  pointed to http://localhost/. Rewrote to relative URL.
Updated "Archive of Okrandian Canon" search.

* Minor update to make the CGI script of "Archive of Okrandian Canon"
  incorporate stuff from "The {pIqaD} Playground".
Minor formatting change of the KA presentation.