Bundle VS Code node_modules to avoid yarn dependency

Many random bizarre issues otherwise.

Also includes misc improvements to docs and scripts.

ci/dev/diff-vscode.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+main() {
+  cd "$(dirname "$0")/../.."
+
+  cd ./lib/vscode
+  git diff HEAD > ../../ci/dev/vscode.patch
+}
+
+main "$@"

ci/dev/patch-vscode.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+main() {
+  cd "$(dirname "$0")/../.."
+
+  cd ./lib/vscode
+  git apply ../../ci/dev/vscode.patch
+}
+
+main "$@"