Provide some examples for how to interact with a Geth Rollup

[jbowen93]

Related to: #77

We should have an additional section in the README.md or a different Markdown file that gives some copy-paste examples of interacting with the rollup.

It may be best for this to link to https://github.com/astriaorg/astria-web3 but the desire is to make it easy for an end user to see that the rollup is working.

[jbowen93]

Going through the README of https://github.com/astriaorg/astria-web3 you need to specify a JSON_RPC environment variable. This is listed in the dev-cluster README in the Metamask section as:

http://executor.<rollup name>.localdev.me

It might be good to update the table here or create a new table with URLs of the different services.

[jbowen93]

Going through the README of https://github.com/astriaorg/astria-web3 you need to specify a JSON_RPC environment variable. This is listed in the dev-cluster README in the Metamask section as:

executor.<rollup name>.localdev.me

It might be good to update the table here or create a new table with URLs of the different services.

This is actually handled by the .env file having the appropriate JSON_RPC value by default