You don’t have to install files into the workspace from the terminal per se, it’s just how Go structures it’s package management. Basically here’s the gist of the situation, you set up a src, bin, and pkg directory tree under your workspace.
Any source code you write, should be done in the src directory.
Go
------->src
{Folder} *.go files and other source code for your app
------>pkg
{Folder} you will never put anything here yourself, running { go install } in a src folder directory from terminal will compile your code and install it in pkg folder to be used in any future projects as an include
------>bin
{Folder} again you will never put anything in here yourself, { go install } command from your terminal inside a folder containing src code ( .go files) will build the binary for your app and place it in the bin directory of your GOPATH
If you want to run an app for testing without installing its data to pkg and/or bin you can use the go build command from within the src directory to generate the binary there. I hope this has cleared it up for you.