Added generic build instructions.

docs/software_requirements.md

@@ -25,6 +25,19 @@ permalink: /software-requirements
 * [GTK+ 3](https://www.gtk.org) library, version 3.4 or higher.
 * [Gtkmm](https://www.gtkmm.org) library, version 3.4 or higher.
 * C++20 Compiler (GCC 13 or later, Clang/libc++ 17 or later, Apple Clang 15 or later)
+* [CMake](https://cmake.org), version 3.14 or higher.
+
+### Building from Source
+1. Install the dependencies using your package manager.
+2. Clone or extract GSmartControl source code. We assume the directory is named `gsmartcontrol`.
+3. Build GSmartControl using the following commands:
+```bash
+cd gsmartcontrol
+mkdir build
+cd build
+cmake .. -DCMAKE_BUILD_TYPE=Release
+make
+```
 
 ## Runtime Requirements
 **Note:** The Windows packages already include all the required software.