Update Changelog, mention new settings menu in Readme

Changelog.md

@@ -4,6 +4,30 @@ dhewm3 Changelog
 Note: Numbers starting with a "#" like #330 refer to the bugreport with that number
       at https://github.com/dhewm/dhewm3/issues/
 
+1.5.4 (WIP)
+------------------------------------------------------------------------
+
+* A brand new settings menu that uses [Dear ImGui](https://github.com/ocornut/imgui).  
+  Can be opened with `F10` (unless that key is bound already) or by entering `dhewm3Settings`
+  in the console. It has lots of settings that the original options menu doesn't have and
+  can be easily navigated with gamepad or keyboard (or the mouse, of course).
+  It can also be opened while in the game, which then is paused (if Single Player) but still visible,
+  so the effect of most graphics settings can be seen immediately.
+  Needs SDL2 and C++11.
+* Replaced dependency on (external) zlib with integrated [miniz](https://github.com/richgel999/miniz)
+* HighDPI/Retina support
+* Allow inverted mouse look (horizontally, vertically or both) with `m_invertLook`
+* CVar to allow always run in single player (still drains stamina though!): `in_allowAlwaysRunInSP`
+* VSync can be enabled/disabled on the fly, without restarting the renderer (still with `r_swapInterval`
+  or in the menu, of course; needs SDL2)
+* Allow enabling/disabling [HRTF](https://en.wikipedia.org/wiki/Head-related_transfer_function)
+  with `s_alHRTF`
+* `s_alOutputLimiter`: Configure OpenAL's output-limiter which temporarily reduces the overall
+  volume when too many too loud sounds play at once, to avoid issues like clipping
+* `s_scaleDownAndClamp`: Clamp and reduce volume of all sounds to prevent clipping or temporary
+  downscaling by OpenAL's output limiter
+
+
 1.5.3 (2024-03-29)
 ------------------------------------------------------------------------
 

Configuration.md

@@ -200,7 +200,8 @@ This can be configured with the following CVars:
 - `in_kbd` allows you to set your keyboard layout so the console key works better. Mostly useful with SDL1.2
 - `in_tty` tab completion and history for input from the **terminal** (on Unix-likes, like Linux, macOS, BSD, ...)
 
-- `r_fullscreenDesktop` `0`: "real"/"exclusive" fullscreen mode, might switch screen resolution  
+- `r_fullscreenDesktop` configures fullscreen windows (when `r_fullscreen` is `1`).  
+  `0`: "real"/"exclusive" fullscreen mode, might switch screen resolution  
   `1`: "desktop" fullscreen mode, which keeps desktop resolution and is more like a borderless fullscreen window
 - `r_fillWindowAlphaChan` Make sure alpha channel of windows default framebuffer is completely opaque
   at the end of each frame. Needed at least when using Wayland.  

README.md

@@ -35,6 +35,7 @@ Compared to the original _DOOM 3_, the changes of _dhewm 3_ worth mentioning are
 - Better support for widescreen (and arbitrary display resolutions)
 - A portable build system based on CMake
 - (Cross-)compilation with MinGW-w64
+- An advanced, mod-independent settings menu (opened with `F10` by default)
 
 See [Changelog.md](./Changelog.md) for a more complete changelog.
 
@@ -59,7 +60,7 @@ See https://dhewm3.org/#how-to-install for game data installation instructions.
 ## Configuration
 
 See [Configuration.md](./Configuration.md) for dhewm3-specific configuration, especially for 
-using gamepads.
+using gamepads or the new settings menu.
 
 ## Compiling