Add gen-vscode-manual-config command and config

At work, my VSCode config can only be edited through the VSCode GUI. In
order to version control it, check it in to homegit and add a small
Python program that merges common (shared by home and work) config with
work-specific config.

Relevant issues:
- gitpod-io/openvscode-server#199
- gitpod-io/openvscode-server#535
- microsoft/vscode#15909

.config/vscode-manual-config/common.json5

@@ -0,0 +1,16 @@
+{
+    "workbench.colorTheme": "Default Dark Modern",
+    "keyboard.dispatch": "keyCode",
+    "vim.vimrc.enable": true,
+    "[python]": {
+        "editor.defaultFormatter": "ms-python.python"
+    },
+    "vim.handleKeys": {
+        "<C-p>": false,
+    },
+    "vim.useSystemClipboard": true,
+    "files.autoSave": "onFocusChange",
+    "editor.autoClosingBrackets": "never",
+    "security.workspace.trust.untrustedFiles": "open",
+    "files.insertFinalNewline": true,
+}

bin/gen-vscode-manual-config

@@ -0,0 +1,27 @@
+#!/usr/bin/env python3
+import json5
+import os
+from pathlib import Path
+
+
+def main():
+    with open(
+        Path(os.environ["HOME"]) / ".config/vscode-manual-config/common.json5"
+    ) as f:
+        common = json5.load(f)
+
+    try:
+        with open(
+            Path(os.environ["HOME"]) / ".config/vscode-manual-config/local.json5"
+        ) as f:
+            local = json5.load(f)
+    except:
+        local = {}
+
+    merged = common | local
+
+    print(json5.dumps(merged, indent=4))
+
+
+if __name__ == "__main__":
+    main()