First checks to see if `asdf` is installed. If it is, checks to see if either of
the plugins ( `golang` or `go-sdk` ) that install a version of Go have an
installed version. If they do, use that version.
If `asdf` isn't installed, check the `go.mod` file. If in a folder that has a
`go.mod` or a parent folder has a `go.mod`, check that file for the Go version.
Lastly, check if there's a `go` executable on the current path. If there isn't
set a flag so that the go version will be printed out in red rather than blue.
* Add FNM as an alternative to NVM
* Made the __bobthefish_prompt_nvm generic for nvm and fnm
* Hide errors on node_manager current
* Check for color_nvm and set color_node based on that
