Update contributing section

Hoping this will encourage more non-plugin contributions.

README.md

@@ -20,8 +20,15 @@ For more information on Processor and Aggregator plugins please [read this](./do
 New plugins are designed to be easy to contribute,
 we'll eagerly accept pull
 requests and will manage the set of plugins that Telegraf supports.
-See the [contributing guide](CONTRIBUTING.md) for instructions on writing
-new plugins.
+
+## Contributing
+
+There are many ways to contribute:
+- Fix and [report bugs](https://github.com/influxdata/telegraf/issues/new)
+- [Improve documentation](https://github.com/influxdata/telegraf/issues?q=is%3Aopen+label%3Adocumentation)
+- [Review code and feature proposals](https://github.com/influxdata/telegraf/pulls)
+- Answer questions on github and on the [Community Site](https://community.influxdata.com/)
+- [Contribute plugins](CONTRIBUTING.md)
 
 ## Installation:
 
@@ -240,9 +247,3 @@ formats may be used with input plugins supporting the `data_format` option:
 * [socket_writer](./plugins/outputs/socket_writer)
 * [tcp](./plugins/outputs/socket_writer)
 * [udp](./plugins/outputs/socket_writer)
-
-## Contributing
-
-Please see the
-[contributing guide](CONTRIBUTING.md)
-for details on contributing a plugin to Telegraf.