Add build instructions and remove end-of-life Qt5 support

README.md

@@ -1,12 +1,12 @@
 SMTP Client for Qt (C++) - Version 2.0 ![Linux Build](https://github.com/bluetiger9/SmtpClient-for-Qt/actions/workflows/linux-build.yml/badge.svg)
 =============================================
 
-The SmtpClient for Qt is small library written for Qt 5 / 6 (C++ version) that allows application to send complex emails (plain text, html, attachments, inline files, etc.) using the Simple Mail Transfer Protocol (SMTP).
+The SmtpClient for Qt is small library written for Qt 6 (C++ version) that allows application to send complex emails (plain text, html, attachments, inline files, etc.) using the Simple Mail Transfer Protocol (SMTP).
 
 ## New in version 2.0:
 - Asynchronous & Synchronous working mode
 
-- Qt5/6 compatibility
+- Qt6 compatibility
 
 - Building as a shared library
 
@@ -105,9 +105,28 @@ int main(int argc, char *argv[])
 
 For more examples see the [Wiki/Examples](https://github.com/bluetiger9/SmtpClient-for-Qt/wiki/Examples).
 
+## Building
+
+### Building CMake
+
+To build the project with CMake run the following comamnds:
+```sh
+$ cmake . -DQt6_DIR="/qt/install/loccation/6.x.x/6.x.x/gcc_64/lib/cmake/Qt6" -DCMAKE_INSTALL_PREFIX="../release"
+$ cmake --build ../
+$ cmake --install ../
+```
+
+### Building with QMake
+
+To build the project with QMake run the following comamnds:
+```sh
+$ /qt/install/loccation/6.x.x/6.x.x/gcc_64/bin/qmake .
+$ make
+```
+
 ## License
 
 This project (all files including the demos/examples) is licensed under the GNU LGPL, version 2.1.
 
 
-**Copyright (c) 2014-2022 - Attila Tőkés**
+**Copyright (c) 2014-2024 - Attila Tőkés**