src/goMain: update the link to modules doc

Wiki page was replaced with docs/modules.md.
Also, change the command id to go.open.modulesdoc

Change-Id: I42c8422b88949786231d0b8cba6351bcadf38a85
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/238017
Reviewed-by: Rebecca Stambler <rstambler@golang.org>

Author: hyangah

src/goMain.ts

@@ -148,10 +148,10 @@ export function activate(ctx: vscode.ExtensionContext): void {
 	initCoverageDecorators(ctx);
 
 	ctx.subscriptions.push(
-		vscode.commands.registerCommand('go.open.modulewiki', async () => {
+		vscode.commands.registerCommand('go.open.modulesdoc', async () => {
 			vscode.commands.executeCommand(
 				'vscode.open',
-				vscode.Uri.parse('https://github.com/microsoft/vscode-go/wiki/Go-modules-support-in-Visual-Studio-Code')
+				vscode.Uri.parse('https://github.com/golang/vscode-go/blob/master/docs/modules.md')
 			);
 		})
 	);

src/goStatus.ts

@@ -18,7 +18,7 @@ const statusBarItemModule = vscode.window.createStatusBarItem(vscode.StatusBarAl
 statusBarItemModule.text = '$(megaphone) Go Modules';
 statusBarItemModule.tooltip =
 	'Modules is enabled for this project. Click to learn more about Modules support in VS Code.';
-statusBarItemModule.command = 'go.open.modulewiki';
+statusBarItemModule.command = 'go.open.modulesdoc';
 
 export function showHideStatus(editor: vscode.TextEditor) {
 	if (statusBarEntry) {