Bundle brainstorm server dependencies instead of requiring npm install

Vendor node_modules into the repo so the brainstorm server works
immediately on fresh plugin installs without needing npm at runtime.

skills/brainstorming/scripts/node_modules/is-binary-path/index.d.ts

@@ -0,0 +1,17 @@
+/**
+Check if a file path is a binary file.
+
+@example
+```
+import isBinaryPath = require('is-binary-path');
+
+isBinaryPath('source/unicorn.png');
+//=> true
+
+isBinaryPath('source/unicorn.txt');
+//=> false
+```
+*/
+declare function isBinaryPath(filePath: string): boolean;
+
+export = isBinaryPath;