Add base configuration

- Follow XDG standard: ~/.config and ~/.local folders
- Set environment variables and define aliases within ~/.config/shell
- Add installation script for easy setup
- Add README.md with info on the installation and general notes

.zshrc

@@ -0,0 +1,7 @@
+#!/bin/zsh
+
+# `zsh`-specific configurations
+
+
+# Load configuration files common to all kinds of shells
+[ -f "$HOME/.profile" ] && . "$HOME/.profile"