docs: add new badge (#2194)

**Description**

Please explain the changes you made here.

**Checklist**

- [ ] Code compiles correctly and linting passes locally
- [ ] For all _code_ changes, an entry added to the `CHANGELOG.md` file
describing and linking to
      this PR
- [ ] Tests added for new functionality, or regression tests for bug
fixes added as applicable
- [ ] For public APIs, new features, etc., PR on [docs
repo](https://github.com/hypermodeinc/docs)
      staged and linked here

**Instructions**

- The PR title should follow the [Conventional
Commits](https://www.conventionalcommits.org/)
  syntax, leading with `fix:`, `feat:`, `chore:`, `ci:`, etc.
- The description should briefly explain what the PR is about. In the
case of a bugfix, describe or
  link to the bug.
- In the checklist section, check the boxes in that are applicable,
using `[x]` syntax.
- If not applicable, remove the entire line. Only leave the box
unchecked if you intend to come
    back and check the box later.
- Delete the `Instructions` line and everything below it, to indicate
you have read and are
  following these instructions. 🙂

Thank you for your contribution to Badger!

Author: enlightened88

README.md

@@ -5,6 +5,7 @@
 [![Sourcegraph](https://sourcegraph.com/github.com/hypermodeinc/badger/-/badge.svg)](https://sourcegraph.com/github.com/hypermodeinc/badger?badge)
 [![ci-badger-tests](https://github.com/hypermodeinc/badger/actions/workflows/ci-badger-tests.yml/badge.svg)](https://github.com/hypermodeinc/badger/actions/workflows/ci-badger-tests.yml)
 [![ci-badger-bank-tests](https://github.com/hypermodeinc/badger/actions/workflows/ci-badger-bank-tests.yml/badge.svg)](https://github.com/hypermodeinc/badger/actions/workflows/ci-badger-bank-tests.yml)
+[![ci-badger-bank-tests-nightly](https://github.com/hypermodeinc/badger/actions/workflows/ci-badger-bank-tests-nightly.yml/badge.svg)](https://github.com/hypermodeinc/badger/actions/workflows/ci-badger-bank-tests-nightly.yml)
 
 ![Badger mascot](images/diggy-shadow.png)