Update README with relocation and redirect info
This project has been relocated to grails-core as of Grails 7.
the gh-pages branch is used to redirect all https://views.grails.org/ URLs to https://grails.apache.org/docs-legacy-views/
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This project has been relocated to grails-core as of Grails 7.
the gh-pages branch is used to redirect all https://views.grails.org/ URLs to https://grails.apache.org/docs-legacy-views/