Eo extension update readme

[anayeaye]

Related Issue(s): #
N/A This PR addresses issue raised by @lossyrob in STAC/Lobby.

The README here https://github.com/radiantearth/stac-spec/tree/dev/extensions, under the section “Prefixes”, makes it seem like extension prefixes (like eo) are for keys in the properties object of the Item (this is also how https://github.com/radiantearth/stac-spec/blob/dev/extensions/eo/examples/example-landsat8.json is set up). The examples in https://github.com/radiantearth/stac-spec/blob/dev/extensions/eo/README.md make it seem like they go direclty into the body of the Item object. Is this a misplacement in the latter? Is extension Item information explicitly supposed to go into the properties object of the Item?

Proposed Changes:

1. Modifies examples in Assets Object section of EO extension README to place eo:bands inside of item properties and corrects a linked example JSON.
2. Updates Prefixes section of extension README with eo:gsd in place of eo:resolution.

PR Checklist:

• This PR has no breaking changes.
• I have added my changes to the CHANGELOG or a CHANGELOG entry is not required. Documentation changes only.
• API only: I have run npm run generate-all to update the generated OpenAPI files. No API changes.

[m-mohr]

I made some further changes until I realized that this PR - unfortunately - bases on master, not dev. So it's likely that we are working on an outdated example and that's why stac_version, stac_extensions etc are missing. Therefore this PR needs to be done again, basing it on dev instead of master, sorry.

[anayeaye]

@m-mohr Sorry about that! I'll walk though it again and will add your changes as well