Improve GETSTARTED.md as suggested by
- Software requirements
- We need to install some basic tools to run Elektra: cmake , git , and essential build tools (make, gcc, and some standard Unix tools; alternatively [ninja](https://ninja-build.org/) and [clang](https://clang.llvm.org/index.html) are also supported but not described here). Depending on your Linux distribution use following commands to install these tools:
+ We need to install some basic tools to run Elektra: cmake, git and essential build tools (make, gcc, and some standard Unix tools; alternatively [ninja](https://ninja-build.org/) and [clang](https://clang.llvm.org/index.html) are also supported but not described here). Depending on your Linux distribution use the following commands to install these tools:
```sh
sudo apt-get install cmake git build-essential
sudo yum install -y cmake git gcc-c++
```
- Or on macOS, most of the build tools can be obtained by installing [Xcode](https://developer.apple.com/xcode/). Other required tools may be installed using [brew](https://brew.sh/). First install brew as described on their website. Then issue the following command to get cmake to complete the basic requirements:
+ Or on macOS, most of the build tools can be obtained by installing [Xcode](https://developer.apple.com/xcode/). Other required tools may be installed using [brew](https://brew.sh/). First, install brew as described on their website. Then issue the following command to get cmake to complete the basic requirements:
```sh
brew install cmake git
