add some badges to the readme

[v0lkan]

I really liked the layout here:

https://github.com/teletrace/teletrace/blob/main/README.md

We can add some of these to both the GitHub README, and also to the website (if/when relevant)

<div align="center">

[![Slack](https://img.shields.io/badge/slack-teletrace-brightgreen.svg?logo=slack)](https://join.slack.com/t/teletrace/shared_invite/zt-1qv0kogcn-KlbBB2yS~gUCGszZoSpJfQ)
[![Version](https://img.shields.io/github/v/release/teletrace/teletrace?color=blueviolet)](https://github.com/teletrace/teletrace/releases)
[![Commits](https://img.shields.io/github/commits-since/teletrace/teletrace/latest?color=ff69b4&include_prereleases)](https://github.com/teletrace/teletrace/graphs/commit-activity)
[![Merge Queue](https://img.shields.io/endpoint.svg?url=https://api.mergify.com/v1/badges/teletrace/teletrace&style=flat)](https://github.com/teletrace/teletrace/actions/workflows/merge-queue.yml)
[![Docs](https://github.com/teletrace/teletrace/actions/workflows/docs.yml/badge.svg)](https://docs.teletrace.io/)
[![Go Report](https://img.shields.io/badge/go%20report-A+-brightgreen.svg?color=blue)](https://goreportcard.com/report/github.com/teletrace/teletrace)
[![Contributors](https://img.shields.io/github/contributors/teletrace/teletrace.svg?color=orange)](https://github.com/teletrace/teletrace/graphs/contributors)
[![License](https://img.shields.io/badge/License-Apache_2.0-blue.svg?color=red)](https://github.com/teletrace/teletrace/blob/main/LICENSE)

</div>

<h3 align="center">
  <a href="https://docs.teletrace.io/"><b>📝 Explore the docs</b></a> &bull;
  <a href="https://join.slack.com/t/teletrace/shared_invite/zt-1qv0kogcn-KlbBB2yS~gUCGszZoSpJfQ"><b>💬 Join Our Slack</b></a> &bull;
  <a href="https://github.com/teletrace/teletrace/issues/new?assignees=&labels=&template=bug_report.md&title="><b>🐛 Report Bug</b></a> &bull;
  <a href="https://github.com/teletrace/teletrace/issues/new?assignees=&labels=&template=feature_request.md&title="><b>✨ Request Feature</b></a>
</h3>

[v0lkan]

A second look show all the readme there is well-laid out; we can inspire/copy some of the formatting.