Auto: ablegacy-11 — RSLogix 500/PLC-5 CSV symbol import

Closes #254

docs/DriverClis.md

@@ -67,6 +67,19 @@ their flag values to the already-shipped driver.
   then the other. The plausible result identifies the correct setting
   for that device family. (Modbus, S7.)
 
+## Family-specific commands
+
+Most drivers ship the four shared verbs and nothing else. AB Legacy adds a
+fifth family-specific verb for bulk symbol-table import:
+
+| Driver | Extra verb | Doc |
+|---|---|---|
+| AB Legacy | `import-rslogix` — read RSLogix 500/5 CSV symbol exports + emit a JSON tag fragment | [drivers/AbLegacy-RSLogix-Import.md](drivers/AbLegacy-RSLogix-Import.md) |
+
+Binary RSLogix project files (`.RSS` / `.RSP`) are out of scope for v1 — the
+format is proprietary and undocumented; no parser ships in libplctag or any
+community library. Export to CSV first.
+
 ## Known gaps
 
 - **AB Legacy cip-path quirk** — libplctag's ab_server requires a