Updated The Workspace Proposal Prototype (markdown)

The-Workspace-Proposal-Prototype.md

@@ -4,10 +4,71 @@ The [Workspace proposal](https://github.com/golang/go/issues/45713) aims to impr
 
 Please read the [Workflows](https://go.googlesource.com/proposal/+/master/design/45713-workspace.md#workflows) section of the Workspace proposal design document for more information about the workflows the proposal aims to address and how it addresses them. If you have a multi-module workflow that you'd like improved, please give feedback on the [proposal issue](#45713) on how the prototype does or does not help.
 
+For those of you who are more visually oriented, here's a video: 
+
+```
+// TODO(matloob): finish the video and put it here
+```
+
 # Setting up the Go command
 
+To try the prototype, download the `gotip` command, which allows you to use alternate versions of the `go` command, including this prototype. Do so by running
+
+```
+go install golang.org/dl/gotip@latest
+```
+
+if you're on Go 1.16 or later. For older versions of Go, install the tool using the old `go get way`: `go get golang.org/dl/gotip`.
+
+`gotip` needs to be initialized with a version of `go` to run for you. That's done by running `gotip download`. In our case, we'll download the `dev.cmdgo` branch of the Go repository, which holds the source for the workspace prototype:
+
+```
+gotip download dev.cmdgo
+```
+
+This will download and compile the code for the prototype and make it available from the `gotip` command.
+
+`gotip` can then be used exactly like the go command. For example you can run `gotip build ...` or `gotip run ...`.
+
+# The workspace file format
+
+Workspaces are defined using `go.work` files. If your current directory contains a `go.work` file (or it's under a directory that does) the Go command will be put into workspace mode when doing a build (this is similar to how a `go.mod` file defines the scope of a module). When in a workspace, instead of using the closest containing `go.mod` to figure out what module you're in, the `go` command uses the closest containing `go.work` to figure out what _workspace_ you're in. All the modules specified in that workspace become your main modules! You can build all of that code from any directory in the workspace.
+
+Let's look at a `go.work` file:
+
+```
+go 1.17
+
+directory (
+    ./baz // foo.org/bar/baz
+    ./tools // golang.org/x/tools
+)
+
+replace golang.org/x/net => example.com/fork/net v1.4.5
+```
+
+The syntax is intentionally similar to `go.mod`'s syntax. We have three directives: the `go` directive, the `directory directive, and the `replace` directive. The `go` and `replace` directives are there for backwards compatibility reasons (see the proposal doc for more details), behave similarly to their counterparts in `go.mod`, and have the same syntax. The `directory` directive allows you to specify which modules you're working in (by the directory containing the `go.mod` file. These are the modules that become the main modules in the workspace.
+
 # Setting up `gopls`
 
+You'll need to add a bit of configuration to test out `gopls` with the workspace proposal prototype. You'll need to tell your editor to use an alternate version of Go.
+
+If you've already got VS Code set up with Gopls, You'll need to add the following entry to your settings.json:
+`
+{
+    ...
+    "go.alternateTools": {
+        "go": "gotip"
+    }
+    ...
+}
+`
+so that it knows to use `gotip` as the go tool.
+
+For other editors see [the configuration section of the gopls docs](https://github.com/golang/tools/blob/master/gopls/README.md#configuration) for information for how to set an alternate `go` tool.
+
 # Known issues with the prototype
 * Replace directives are not yet supported in the `go.work` file.
-# Giving Feedback
+# Giving Feedback
+
+Feel free to post all feedback on the issue #45713. Alternatively, you can send Michael Matloob a slack message, an email at their last name at golang dot org, or send a message at their last name on twitter.