Bug: Missing `.dev.vars.example` file referenced in README

Summary

The README instructs developers to copy .dev.vars and populate it with their ThoughtSpot instance URL and access token, but no .dev.vars.example template file exists in the repository.

Steps to Reproduce

1. Clone the repository
2. Follow the README setup instructions: "Copy .dev.vars and fill in your ThoughtSpot instance URL and access token"
3. Observe that there is no .dev.vars or .dev.vars.example file to copy from

Expected Behaviour

A .dev.vars.example file should be committed to the repository containing the required variable names with placeholder values, e.g.:

TS_INSTANCE=https://your-instance.thoughtspot.cloud                     
TS_AUTH_TOKEN=your-access-token-here  

Actual Behaviour

No template file exists. .dev.vars is correctly listed in .gitignore (confirming it was always intended to be a local-only file), but the corresponding .dev.vars.example template was never committed. Developers have no way to know what variables are required or their expected format without reading the source code directly.

Impact

This breaks the getting started experience for new developers — the setup instructions cannot be followed as written.

Suggested Fix

• Add a .dev.vars.example file to the repository root with all required (and optional) variable names and placeholder values
• Update the README to reference .dev.vars.example as the file to copy, e.g. cp .dev.vars.example .dev.vars

Start with the README setup instructions and the repository’s .gitignore to confirm the intended local-only file name. Check the source for required and optional variable names, add the root .dev.vars.example with placeholders, and update the README to copy it to .dev.vars. Done means a new developer can follow the documented setup without reading source code.