Housekeeping - documentation update.

Introduced a new dependency checking script that validates required apt packages before building the project

Documented the expanded package list and instructions for running the script within the build prerequisites documentation

Updated build system instructions to call the dependency checker prior to configuring with CMake

README.md

@@ -57,20 +57,34 @@ https://github.com/user-attachments/assets/9a9fd0c6-78fc-4284-8b44-6a1929c00cc6
 ### [Command-Line Configuration of PiPedal](https://rerdavies.github.io/pipedal/CommandLine.html)
 ### [Changing the Web Server Port](https://rerdavies.github.io/pipedal/ChangingTheWebServerPort.html)
 
-%nbsp;
+ 
 
 ### [Using LV2 Audio Plugins](https://rerdavies.github.io/pipedal/UsingLv2Plugins.md)
 ### [Which LV2 Plugins does PiPedal support?](https://rerdavies.github.io/pipedal/WhichLv2PluginsAreSupported.html)
 ### [Support for LV2 Plugins with MOD User Interfaces](https://rerdavies.github.io/pipedal/ModUiSupport.html)
 
-  
+ 
 
 ### [Building PiPedal from Source](https://rerdavies.github.io/pipedal/BuildingPiPedalFromSource.html)
 ### [Build Prerequisites](https://rerdavies.github.io/pipedal/BuildPrerequisites.html)
 ### [The Build System](https://rerdavies.github.io/pipedal/TheBuildSystem.html)
+### Setup
+
+Fetch the project's submodules before building:
+
+```sh
+git submodule update --init --recursive
+```
+
+After running this command the following directories should be populated:
+
+- `modules/SQLiteCpp`
+- `modules/websocketpp`
+- `submodules/pipedal_p2pd`
+
 ### [How to Debug PiPedal](https://rerdavies.github.io/pipedal/Debugging.html)
 
-  
+ 
 
 #### [PiPedal Architecture](https://rerdavies.github.io/pipedal/Architecture.html)