XDG Base Directory specification not used properly

[gudvinr]

Describe the bug A clear and concise description of what the bug is.

To Reproduce Steps to reproduce the behavior:

1. Download install.sh
2. Make it executable
3. Run install.sh

Expected behavior Honoring XDG Base Directory specifications and not installing binaries and all of the data files into $HOME/.config which is default $XDG_CONFIG_HOME and shouldn't be hardcoded in first place.

Additional context According to XDG Base Directory specification: There is a single base directory relative to which user-specific configuration files should be written. This directory is defined by the environment variable $XDG_CONFIG_HOME.

$XDG_CONFIG_HOME (which is $HOME/.config by default) should not be used for storing executables, app data, downloads, etc because its intended use is to store configuration files. It is also often synchronized or backed up.

Proper place for installation directory would be $HOME/.local/opt or even just $HOME/.fusion-360.

As a bonus it would be much appreciated to redefine installation and download directories through environment variables to make installation flexible. People often make their own directory structure to install software locally.

[cryinkfly]

@gudvinr Thank you for pointing this out! I've already found that this location for storing the executables wasn't the best choice. That's why I change the entire structure again. :+1: