wiki: add Carbon Design System icons (2673) + pictograms (1000)

- 2673 SVG icons from @carbon/icons v11.82.0 (~2.5 MB)
- 1000 SVG pictograms from Carbon Design System (~2.0 MB)
- Updated 00-overview.md with asset structure and category listing

All icons: 32x32, fill: currentColor, optimized SVG
All pictograms: 24x24, fill: currentColor, SVG

assets/icons/carbon/ibm-watson-natural-language-understanding.svg

@@ -0,0 +1,15 @@
+<!-- Generator: Adobe Illustrator 26.3.1, SVG Export Plug-In . SVG Version: 6.00 Build 0) -->
+<svg version="1.1" id="icon" x="0px" y="0px" width="32px" height="32px" viewBox="0 0 32 32" style="enable-background:new 0 0 32 32;" xml:space="preserve">
+<style type="text/css"> .st0{fill:none;}
+</style>
+<rect x="6" y="23" width="5" height="2"/>
+<rect x="6" y="19" width="5" height="2"/>
+<path d="M13,30H4c-1.1,0-2-0.9-2-2V17c0-1.1,0.9-2,2-2h9c1.1,0,2,0.9,2,2v11C15,29.1,14.1,30,13,30z M4,17v11h9V17H4z"/>
+<rect x="19" y="2" width="8" height="2"/>
+<rect x="22" y="6" width="8" height="2"/>
+<rect x="22" y="10" width="8" height="2"/>
+<rect x="19" y="14" width="8" height="2"/>
+<rect x="22" y="18" width="8" height="2"/>
+<path d="M12,1l-1.4,1.4L13.2,5H4C2.9,5,2,5.9,2,7v5h2V7h9.2l-2.6,2.6L12,11l5-5L12,1z"/>
+<rect id="_x3C_Transparent_Rectangle_x3E__232_" y="0" class="st0" width="32" height="32"/>
+</svg>