People reading this doc may not know, how versions in "go get" work
or how Git tags map to Go module versions. So, add an example
of getting a specific version of gopls.
Change-Id: Id75cc8829bbbf710c3c021eab7d956433ba4110e
Reviewed-on: https://go-review.googlesource.com/c/tools/+/246418
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
Fixes this problem when trying to use the documented installation command:
```
$ GO111MODULE=on go get golang.org/x/tools gopls@latest
go: finding golang.org/x/tools latest
go: downloading golang.org/x/tools v0.0.0-20190911230505-6bfd74cf029c
go: extracting golang.org/x/tools v0.0.0-20190911230505-6bfd74cf029c
go get gopls@latest: malformed module path "gopls": missing dot in first path element
```
Change-Id: Ifdd13ec85eca5a069c17ae89486efe1abf4016f4
GitHub-Last-Rev: a4ddc02e3b8e6ccce12dfa711a8e7af5edb1302c
GitHub-Pull-Request: golang/tools#158
Reviewed-on: https://go-review.googlesource.com/c/tools/+/195037
Reviewed-by: Ian Cottrell <iancottrell@google.com>
Much of this documentation has been collated from other sources,
but this pulls it all into one coherent and public structure in
a way that allows us to peer review changes.
Change-Id: Ic24a59bb92b27ec85d2f57affcf2eb396c9de3c0
Reviewed-on: https://go-review.googlesource.com/c/tools/+/191741
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
