docs/nightly: move README.md.nightly to its own directory

Hana, let me know if you don't like this change. I was just thinking
that it might be confusing for people to see 2 READMEs and 2 CHANGELOGs
at the top level. This way, we can keep this documentation separate.

Also modified the nightly README so that the information is a little
more up-to-date.

Change-Id: I6086ab0950d0fb56d3d5dfd789b45ca88985b7d7
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/236281
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
diff --git a/README.md.nightly b/README.md.nightly
deleted file mode 100644
index 0064e7e..0000000
--- a/README.md.nightly
+++ /dev/null
@@ -1,27 +0,0 @@
-# Go Nightly for VS Code
-
-> ### **ATTENTION**
->**Go Nightly for VS Code** is the insider version of
-[VS Code Go extension](https://github.com/microsoft/vscode-go)
-for early feedback and testing. This extension works best with
-[VS Code Insiders](https://code.visualstudio.com/insiders).
-Go Nightly contains previews of new features and bug fixes that are still
-under review or testing, so can be unstable. If you are looking for the stable version,
-please use [the stable version](https://marketplace.visualstudio.com/items?itemName=ms-vscode.go) instead.
->
-> **NOTE:**
-If you have both stable (aka "Go") and nightly version (aka "Go Nightly") installed,
-you MUST DISABLE one of them. Docs on how to disable an extension can be found
-[here](https://code.visualstudio.com/docs/editor/extension-gallery#_disable-an-extension).
-
-> ### Difference between VS Code Go and VS Code Go Nightly
-> - Go Nightly is maintained and released by Go Tools team at Google.
-> - Go Nightly is released more frequently than the stable version.
-> - Go Nightly includes features and bug fixes that are still under testing or not finalized yet.
-> - Go Nightly may use the latest pre-release versions of tools (e.g. `gopls`) instead of release versions.
-> - For now, Go and Go Nightly maintain separate repositories. Both repositories
->   welcome all contributors. For contribution to Go Nightly repo, see the Go
->   project's [contribution guide](https://golang.org/doc/contribute.html).
->   Go team members who has signed the Microsoft CLA will send a syncing PR upstream to
->   https://github.com/microsoft/vscode-go every two weeks.
-> - [Here](https://github.com/microsoft/vscode-go/compare/master...golang:master) is the full list of local modifications.
diff --git a/build/all.bash b/build/all.bash
index 6b72279..a8dc87e 100755
--- a/build/all.bash
+++ b/build/all.bash
@@ -77,9 +77,9 @@
 ') > /tmp/package.json && mv /tmp/package.json package.json
 
   # Replace CHANGELOG.md with CHANGELOG.md.nightly + Release commit info.
-  printf "**Release ${VER} @ ${COMMIT}** \n\n" | cat - CHANGELOG.md.nightly > /tmp/CHANGELOG.md.new && mv /tmp/CHANGELOG.md.new CHANGELOG.md
+  printf "**Release ${VER} @ ${COMMIT}** \n\n" | cat - docs/nightly/CHANGELOG.md > /tmp/CHANGELOG.md.new && mv /tmp/CHANGELOG.md.new CHANGELOG.md
   # Replace the heading of README.md with the heading for Go Nightly.
-  sed '/^# Go for Visual Studio Code$/d' README.md | cat README.md.nightly - > /tmp/README.md.new && mv /tmp/README.md.new README.md
+  sed '/^# Go for Visual Studio Code$/d' README.md | cat docs/nightly/README.md - > /tmp/README.md.new && mv /tmp/README.md.new README.md
 }
 
 main() {
diff --git a/docs/nightly.md b/docs/nightly.md
index 776b2f4..2501b98 100644
--- a/docs/nightly.md
+++ b/docs/nightly.md
@@ -1,6 +1,8 @@
 # Go Nightly
 
-This master branch of this extension is built and published nightly through the [Go Nightly](https://marketplace.visualstudio.com/items?itemName=golang.go-nightly). If you're interested in testing new features and bug fixes, you may be interested in switching to the Go Nightly extension. Also, if you file an issue, we may suggest trying out the fix in Go Nightly.
+This master branch of this extension is built and published nightly through the [Go Nightly]. If you're interested in testing new features and bug fixes, you may be interested in switching to the Go Nightly extension. Also, if you file an issue, we may suggest trying out the fix in Go Nightly.
+
+The [Changelog](nightly/CHANGELOG.md) and [README](nightly/README.md) for [Go Nightly] can be found in the [docs/nightly](nightly/) directory.
 
 If you try out Go Nightly, please file issues when you notice bugs. You can also join the maintainers in the [#vscode-dev](https://gophers.slack.com/archives/CUWGEKH5Z) channel on the [Gophers Slack](https://invite.slack.golangbridge.org/).
 
@@ -19,3 +21,5 @@
 3) If prompted, reload VS Code.
 
 **Note**: If you install an extension from a VSIX file, you will stop receiving automatic prompts when updates are released.
+
+[Go Nightly]: https://marketplace.visualstudio.com/items?itemName=golang.go-nightly
diff --git a/CHANGELOG.md.nightly b/docs/nightly/CHANGELOG.md
similarity index 100%
rename from CHANGELOG.md.nightly
rename to docs/nightly/CHANGELOG.md
diff --git a/docs/nightly/README.md b/docs/nightly/README.md
new file mode 100644
index 0000000..20575aa
--- /dev/null
+++ b/docs/nightly/README.md
@@ -0,0 +1,14 @@
+# Go Nightly for VS Code
+
+> ### **ATTENTION: This is the *preview* version of the [VS Code Go extension](https://github.com/golang/vscode-go), used for early feedback and testing.**
+> It is published nightly and contains previews of new features and bug fixes that are still under review or being tested. Therefore, this extension can be broken or unstable at times. If you are looking for the stable version,
+please install [the default VS Code Go extension](https://marketplace.visualstudio.com/items?itemName=golang.go) instead.
+>
+> **NOTE: The stable Go extension (`golang.Go`) cannot be used at the same time as the preview Go Nightly extension (`golang.go-nightly`)**. If you have installed both extensions, you **must disable or uninstall** one of them. For further guidance, read the [documentation on how to disable an extension](https://code.visualstudio.com/docs/editor/extension-gallery#_disable-an-extension).
+
+> ### **Differences between Go and Go Nightly**
+>
+> * Go Nightly is released more frequently than the stable version (once per weekday).
+> * Go Nightly includes features and bug fixes that are not yet finalized.
+> * Go Nightly may use pre-release versions of tools (such as `gopls`) instead of released versions.
+> * For more information about Go Nightly, read the [Go Nightly](../nightly.md) documentation.