Fix typo in package name 'build-essentials' to 'build-essential'

Author: catharanthus

index.md

@@ -37,7 +37,7 @@ This release was published on 2022-08-28 and is based on Qt5. Choose it for olde
 Building SDM from source requires [CMake](https://cmake.org) and [Qt6](https://www.qt.io). For Ubuntu, the prerequisites can be installed as follows:
 
 ```
-sudo apt install build-essentials qt6-base-dev qt6-base-dev-tools libqt6svg6-dev qt6-tools-dev \
+sudo apt install build-essential qt6-base-dev qt6-base-dev-tools libqt6svg6-dev qt6-tools-dev \
 qt6-tools-dev-tools qt6-l10n-tools qt6-translations-l10n qt6-image-formats-plugins cmake
 ```