Standard blurb for pointing to meta

We could have a standard text for each repositiory which states something like:

This crate is part of the georust community, please see [our metapage](https://github.com/georust/meta) for CoC, pull request handling, guidelines, etc..

Review the GeoRust repositories and the linked georust/meta page to find where repository-level notices and community guidance are currently maintained. Confirm which repositories should receive the standard blurb, then ensure the agreed wording links to the meta page and covers the stated community guidance consistently.

Written by the indexing model from the issue text.