docs: add CLI search section to README

Documents the npx CLI search functionality with all variation
prefixes including chubby, duotone, and brands.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

README.md

@@ -100,6 +100,52 @@ data/
 explorer.html           # Interactive icon browser
 ```
 
+## CLI Search
+
+Search for icons directly from the command line using `npx`:
+
+```bash
+# Basic search
+npx @invisi/flaticon-uicons camera
+
+# Search with multiple keywords
+npx @invisi/flaticon-uicons arrow left
+
+# Filter by variation (prefix)
+npx @invisi/flaticon-uicons user rr
+npx @invisi/flaticon-uicons home --variation ss
+```
+
+Outputs JSON with icon names and available variations:
+
+```json
+{
+  "camera": ["rs", "rr", "bs", "br", "ss", "sr", "ts", "tr"],
+  "camera-phone": ["rs", "rr", "bs", "br"]
+}
+```
+
+### Variation Prefixes
+
+| Prefix | Style |
+|:-------|:------|
+| `rs`   | Regular Straight |
+| `rr`   | Regular Rounded |
+| `rc`   | Regular Chubby |
+| `bs`   | Bold Straight |
+| `br`   | Bold Rounded |
+| `bc`   | Bold Chubby |
+| `ss`   | Solid Straight |
+| `sr`   | Solid Rounded |
+| `sc`   | Solid Chubby |
+| `ts`   | Thin Straight |
+| `tr`   | Thin Rounded |
+| `tc`   | Thin Chubby |
+| `ds`   | Duotone Straight |
+| `dr`   | Duotone Rounded |
+| `dc`   | Duotone Chubby |
+| `brands` | Brand Logos |
+
 ## Icon Explorer
 
 Open `explorer.html` in a browser to: