Install Extism runtime in hosted environment without Sudo

The Extism runtime installation instructions recommend using sudo. This is difficult or even impossible in some Wordpress hosted environments. We need some instructions or even an automated/scripted way to install the runtime for this plugin that only requires user permissions.

I think this is primarily a documentation issue or rolling the procedure into a script that can be used. I don't think any code needs to be changed. We should contact the Extism team to see if they have any advice.