DEV: Move vscode config files to .vscode-sample directory (#11943)

We want to allow developers to customize their own vscode environment.
Including launch.json/tasks.json files in the repository makes this very
difficult.

These were originally added for GitHub codespaces. Once codespaces is
more widely available, we can look into automatically copying the
`.vscode-sample` directory to `.vscode` when the codespace boots.

.vscode-sample/launch.json

@@ -0,0 +1,19 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Discourse",
+            "type": "Ruby",
+            "request": "launch",
+            "cwd": "/home/discourse/workspace/discourse", 
+            // run bundle install before rails server
+            "preLaunchTask": "Prepare discourse",
+            "env": { "DISCOURSE_DEV_HOSTS": "${env:CLOUDENV_ENVIRONMENT_ID}-9292.apps.codespaces.githubusercontent.com", "UNICORN_BIND_ALL": "1", "UNICORN_WORKERS": "4", "DISCOURSE_DEV_ALLOW_ANON_TO_IMPERSONATE": "1" },
+            "program": "bin/unicorn",
+            "args": ["-x"],
+        }
+    ]
+}

.vscode-sample/tasks.json

@@ -0,0 +1,12 @@
+{
+    // See https://go.microsoft.com/fwlink/?LinkId=733558
+    // for the documentation about the tasks.json format
+    "version": "2.0.0",
+    "tasks": [
+        {
+            "label": "Prepare discourse",
+            "type": "shell",
+            "command": "cd /home/discourse/workspace/discourse && bundle install && yarn && bin/rake db:migrate"
+        }, 
+    ], 
+}