picom-trans: add page (#8244)

pages/common/picom-trans.md

@@ -0,0 +1,20 @@
+# picom-trans
+
+> Set the window opacity for the `picom` window compositor.
+> More information: <https://github.com/yshui/picom>.
+
+- Set the currently focused window opacity to a specific percentage:
+
+`picom-trans --current --opacity {{90}}`
+
+- Set the opacity of a window with a specific name:
+
+`picom-trans --name {{Firefox}} --opacity {{90}}`
+
+- Set the opacity of a specific window selected via mouse cursor:
+
+`picom-trans --select --opacity {{90}}`
+
+- Toggle the opacity of a specific window:
+
+`picom-trans --name {{Firefox}} --toggle`