Support go install

[guigui64]

It is impossible to use as a command:

$ go get github.com/go-generalize/go2ts
go: go.mod file not found in current directory or any parent directory.
	'go get' is no longer supported outside a module.
	To build and install a command, use 'go install' with a version,
	like 'go install example.com/cmd@latest'
	For more information, see https://golang.org/doc/go-get-install-deprecation
	or run 'go help get' or 'go help install'.

And

$ go install github.com/go-generalize/go2ts@latest
go: downloading github.com/go-generalize/go2ts v1.6.0
go: github.com/go-generalize/go2ts@latest: module github.com/go-generalize/go2ts@latest found (v1.6.0), but does not contain package github.com/go-generalize/go2ts

[54m]

@guigui64
try
go install github.com/go-generalize/go2ts/cmd/go2ts@latest