[ImpRpt] Add cicp_inserter, improve description of pngcheck

Author: svgeesus

Implementation_Report_3e/index.html

@@ -612,7 +612,12 @@ <h2>2. Coding Independent Code Points (CICP) from ITU-R H.273</h2>
                     <ul>
                         <li><a href="https://github.com/AOMediaCodec/libavif/pull/1422">Writes primaries and transfer characteritics info in decoded png</a></li>
                     </ul>
-                    <p>Implemented in <a href="https://github.com/pnggroup/pngcheck"><strong>pngcheck</strong></a>.</p>
+
+                    <p>Implemented in <a href="https://github.com/pnggroup/pngcheck"><strong>pngcheck</strong></a>,
+                    a command-line PNG validator.</p>
+
+                    <p>Implemented in <a href="https://github.com/ProgramMax/cicp_inserter">cicp_inserter </a>,
+                     a command-line tool to add 'cICP' chunks to existing PNG files.</p>
 
                     <section class="tests" id="cicp-chunk">
                         <h3>CICP tests</h3>