Update README (#102)

Updates the README with badges, contributing information, initial
release schedule, and useful links.

README.md

@@ -1,2 +1,54 @@
-[![Join the chat at https://gitter.im/open-telemetry/opentelemetry-ruby](https://badges.gitter.im/open-telemetry/opentelemetry-ruby.svg)](https://gitter.im/open-telemetry/opentelemetry-ruby?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
-[![Build Status](https://travis-ci.org/open-telemetry/opentelemetry-ruby.svg?branch=master)](https://travis-ci.org/open-telemetry/opentelemetry-ruby)
+# OpenTelemetry Ruby
+
+[![Gitter chat][gitter-image]][gitter-url]
+[![Travis CI][ci-image]][ci-url]
+[![Apache License][license-image]][license-image]
+
+The Ruby [OpenTelemetry](https://opentelemetry.io/) client.
+
+## Contributing
+
+We'd love your help! Use tags [good first issue][issues-good-first-issue] and
+[help wanted][issues-help-wanted] to get started with the project.
+
+The Ruby special interest group (SIG) meets regularly. See the OpenTelemetry
+[community page][ruby-sig] repo for information on this and other language SIGs.
+
+
+## Release Schedule
+
+OpenTelemetry Ruby is under active development. Our goal is to release an
+_alpha_ version of the library at the end of September 2019. This release isn't
+guaranteed to conform to a specific version of the specification, and future
+releases will not attempt to maintain backwards compatibility with the alpha
+release.
+
+| Component                   | Version | Target Date       |
+| --------------------------- | ------- | ----------------- |
+| Tracing API                 | Alpha   | September 30 2019 |
+| Tracing SDK                 | Alpha   | September 30 2019 |
+| Metrics API                 | Alpha   | Unknown           |
+| Metrics SDK                 | Alpha   | Unknown           |
+| Jaeger Trace Exporter       | Alpha   | Unknown           |
+| Prometheus Metrics Exporter | Alpha   | Unknown           |
+| OpenTracing Bridge          | Alpha   | Unknown           |
+| OpenCensus Bridge           | Alpha   | Unknown           |
+
+## Useful links
+
+- For more information on OpenTelemetry, visit: <https://opentelemetry.io/>
+- For help or feedback on this project, join us on [gitter][gitter-url].
+
+## License
+
+Apache 2.0 - See [LICENSE][license-url] for more information.
+
+[ci-image]: https://travis-ci.org/open-telemetry/opentelemetry-ruby.svg?branch=master
+[ci-url]: https://travis-ci.org/open-telemetry/opentelemetry-ruby
+[gitter-image]: https://badges.gitter.im/open-telemetry/opentelemetry-ruby.svg
+[gitter-url]: https://gitter.im/open-telemetry/opentelemetry-ruby?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge
+[issues-good-first-issue]: https://github.com/open-telemetry/opentelemetry-ruby/issues?q=is%3Aissue+is%3Aopen+label%3A%22good+first+issue%22
+[issues-help-wanted]: https://github.com/open-telemetry/opentelemetry-ruby/issues?q=is%3Aissue+is%3Aopen+label%3A%22help+wanted%22
+[license-image]: https://img.shields.io/badge/license-Apache_2.0-green.svg?style=flat
+[license-url]: https://github.com/open-telemetry/opentelemetry-ruby/blob/master/LICENSE
+[ruby-sig]: https://github.com/open-telemetry/community#ruby-sig