Update configuration and running locally docs

[lmars]

This updates the README to have separate "Installation", "Configuration" and "Running locally" sections, adds a commented configuration file, and enables the kafka-connect-maven-plugin to output a ZIP file that can be installed into Kafka Connect clusters.

Closes #8

[lmars]

I added 6a19f7c to upload the ZIP archive to sdk.ably.com, for example:

https://sdk.ably.com/builds/ably/kafka-connect-ably/pull/6/ably-kafka-connect-ably-1.0-SNAPSHOT.zip

Once this is merged, it'll be available at:

https://sdk.ably.com/builds/ably/kafka-connect-ably/main/ably-kafka-connect-ably-1.0-SNAPSHOT.zip

[lmars]

So I realised that some docs are rendered out into the target/docs directory by the connect-utils repo (see templates here), but they are Sphinx source files so I've added a GitHub action to render them to HTML and also upload those (see fb941a1), which can now be seen when clicking the "View deployment" button, e.g.:

https://sdk.ably.com/builds/ably/kafka-connect-ably/pull/6/

The nice thing about this is the auto-generated config docs:

https://sdk.ably.com/builds/ably/kafka-connect-ably/pull/6/sinks/ChannelSinkConnector.html

[paddybyers]

Why is this all in the io.ably package? It should be com.ably

[lmars]

Why is this all in the io.ably package? It should be com.ably

I assumed there was some historic reason (e.g. we're registered under io.ably in some packaging system), if that's not the case then yes we should change it. Tracked in https://ably.atlassian.net/browse/INT-8

[paddybyers]

e.g. we're registered under io.ably in some packaging system

Historically that was true for Maven Central, but nonetheless we're now building stuff in com.ably (eg https://github.com/ably/ably-asset-tracking-android)

[Matt-Esch]

👍 LGTM