package.json: let some commands activate extension

go.tools.install, go.locate.tools, and go.show.commands
are useful when checking the dev environment setup
after installing the extension.

Fixes golang/vscode-go#457

Change-Id: I8b06b9c8a1ab5d116ab7688496f243625dd81d1d
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/252826
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Suzy Mueller <suzmue@golang.org>
diff --git a/package.json b/package.json
index 16d43be..fcba719 100644
--- a/package.json
+++ b/package.json
@@ -90,6 +90,8 @@
     "onLanguage:go",
     "onCommand:go.gopath",
     "onCommand:go.tools.install",
+    "onCommand:go.locate.tools",
+    "onCommand:go.show.commands",
     "onDebugResolve:go"
   ],
   "main": "./dist/goMain.js",