Document layer style in l parameter

src/topics/Interfacing.md

@@ -20,7 +20,7 @@ The following parameters can appear in the URL of the QWC2 application:
 
 The `l` parameter lists all layers in the map (redlining and background layers) as a comma separated list of entries of the form
 ```text
-<layername>[<transparency>]!
+<layername>[<transparency>]{<style>}!
 ```
 where
 - `layername` is the WMS name of a theme layer or group, or an external layer resource string in the format
@@ -29,7 +29,8 @@ where
 ```
    for external layers, i.e. `wms:https://wms.geo.admin.ch/?#ch.are.bauzonen`.
 - `<transparency>` denotes the layer transparency, betwen 0 and 100. If the `[<transparency>]` portion is omitted, the layer is fully opaque.
-- `!` denotes that the layer is invisible. If omitted, the layer is visible.
+- `<style>` denotes the layer style name. If the `{<style>}` portion is omitted, the style named `default` will be used, if one exists, or the first available style otherwise.
+- `!` denotes that the layer is invisible (i.e. unchecked in the layer tree). If omitted, the layer is visible.
 
 *Note*: If group name is specified instead of the layer name, QWC2 will automatically resolve this to all layer names contained in that group, and will apply transparency and visibility settings as specified for the group.