all: add support for go.work files as go.mod files

This will allow us to add support for the go.work proposal.

Change-Id: I13b374ede724a5a10f0ad11b1073d7849226a4bf
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/341849
Trust: Rebecca Stambler <rstambler@golang.org>
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
diff --git a/package.json b/package.json
index 73c9d8f..644bac6 100644
--- a/package.json
+++ b/package.json
@@ -131,7 +131,8 @@
         "id": "go.mod",
         "extensions": [
           "go.mod",
-          "gopls.mod"
+          "gopls.mod",
+          "go.work"
         ],
         "aliases": [
           "Go Module File"
diff --git a/src/goLanguageServer.ts b/src/goLanguageServer.ts
index 5014946..317687d 100644
--- a/src/goLanguageServer.ts
+++ b/src/goLanguageServer.ts
@@ -460,7 +460,8 @@
 		// gopls handles only file URIs.
 		{ language: 'go', scheme: 'file' },
 		{ language: 'go.mod', scheme: 'file' },
-		{ language: 'go.sum', scheme: 'file' }
+		{ language: 'go.sum', scheme: 'file' },
+		{ language: 'go.work', scheme: 'file' }
 	];
 
 	// Let gopls know about .tmpl - this is experimental, so enable it only in the experimental mode now.