chore: enhance README with build instructions

Added build instructions for MSVC, Clang, and GCC.

Author: NotRequiem

README.md

@@ -3,6 +3,7 @@
 **ntstrings** is a string extraction tool for Windows. Designed as a high-performance alternative to standard tools like Sysinternals `strings`, `bstrings`, `xxstrings`, `strings2`, etc.
 
 For a more in-depth explanation of the scanning approach, see the [architecture documentation](https://github.com/NotRequiem/ntstrings/blob/master/architecture.md).
+
 # Usage
 
 ```text
@@ -84,3 +85,19 @@ Load a list of malicious strings/indicators from a text file and check an execut
 ```cmd
 ntstrings -fs malicious_iocs.txt suspect.exe
 ```
+
+# Build
+> For MSVC or LLVM clang-cl, just open the .sln file located at the root of this repository and click on "**Build**".
+
+> For Clang or GCC, use CMake, located inside the nstrings folder.
+
+Example on Clang:
+```cmd
+cmake -B build -G "Ninja" ^
+    -DCMAKE_C_COMPILER=clang ^
+    -DCMAKE_CXX_COMPILER=clang++ ^
+    -DCMAKE_BUILD_TYPE=Release
+
+cmake --build build --config Release
+```
+<img width="703" height="389" alt="image" src="https://github.com/user-attachments/assets/0695f09b-ff1d-4c95-85b4-a7bbde6677ab" />