gitignore: add missing demux_generic.9 entry

Luca Toniolo · Luca Toniolo · commit 073f3a5022c6 · 2026-04-07T12:52:01.000+08:00
The demux_generic component added in #3906 missed adding its generated man page to docs/man/.gitignore.
diff --git a/docs/man/.gitignore b/docs/man/.gitignore
@@ -312,6 +312,7 @@ man9/ddt.9
 man9/deadzone.9
 man9/debounce.9
 man9/demux.9
+man9/demux_generic.9
 man9/differential.9
 man9/div2.9
 man9/edge.9
