Add support for custom installation directory

[grasmarcussanti129]

Feature Request: Custom Installation Directory

It would be great if localua.sh allowed users to specify a custom installation directory for Lua and LuaRocks, instead of always installing them in a predefined location like .lua. This could enhance flexibility in managing different Lua environments for various projects.

Proposed Changes:

• Add an option (e.g., --install-dir) that takes a path for the installation directory.
• Update the script to handle this directory for all installations and configurations.

Benefits:

• Users can keep their environments tidy and organized.
• Easy switching between different projects with separate Lua setups.

I believe this enhancement would make localua.sh more versatile for developers managing multiple projects.

[catwell]

Hmm, it already does? Actually, this is the first argument for the script and passing it is mandatory.