Update light inspector section in the user guide

Update the screenshot to reflect the new appearance with the brightness
slider, and mention the function of the slider in the explanatory text.
Also tone down the warning about limitations of the lighting mode
renderer, since this has improved massively and shadows are now
supported.

doc/manual.adoc

@@ -256,9 +256,9 @@ and fully lit by in-game light sources. While the 2D view is the main interface
 for creating and aligning level geometry, the 3D view is a vital tool for tasks
 such as texturing, or configuring light parameters.
 
-IMPORTANT: The fully lit rendering mode in DarkRadiant is very limited, and only
-offers a partial view of what the game engine will ultimately render. In
-particular, there are no shadows or foglights.
+IMPORTANT: The fully lit rendering mode in DarkRadiant is not identical to what
+the game engine will ultimately render. Certain advanced rendering features such
+as reflections and fog lights are not currently supported.
 
 The 3D camera view provides its own toolbar which can be used to configure
 various display settings.
@@ -972,18 +972,24 @@ properties using the light inspector, which is accessed with the *L* key.
 
 image::LightInspector.png[align="center"]
 
+TIP: The light inspector can change the properties of a single light, or
+multiple selected lights simultaneously.
+
 *Light volume (omni vs projected)*:: The majority of lights in a map will be the
-default, omnidirectional shape. An omni light is a simple axis-aligned cuboid
-which emits light in all directions from its center to its edges.
+default, omnidirectional shape. An omni light is a simple cuboid which emits
+light in all directions from its center to its edges.
 +
 A projected light is pyramid-shaped, and emits light from the tip of the pyramid
 towards the base. Projected lights behave more like spotlights in real-life, and
 can be used to highlight particular areas or project images of windows onto the
 floor.
 
 *Colour*:: Use the colour selector button to display a standard colour selection
-dialog, or enter the RGB values directly using the text box. As well as changing
-the hue, the light colour also governs the overall brightness of the light.
+dialog. As well as changing the hue, the light colour also governs the overall
+brightness of the light. You can use the slider below the colour button to
+adjust the brightness of the selected light(s) without changing the hue, with
+realtime feedback displayed in the 3D camera view if lighting preview mode is
+enabled.
 
 *Texture*:: The falloff texture controls the shape of the lit area when rendered
 in-game; the square texture chosen here will be mapped directly onto the