docs: document bootstrap_image_ready option

[praiskup]

No description provided.

[packit-as-a-service]

We were not able to find or create Copr project packit/rpm-software-management-mock-1242 specified in the config with the following error:

Cannot create a new Copr project (owner=packit project=rpm-software-management-mock-1242 chroots=['fedora-rawhide-x86_64']): Response is not in JSON format, there is probably a bug in the API code.

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Please check your configuration for:

1. typos in owner and project name (groups need to be prefixed with @)
2. whether the project name doesn't contain not allowed characters (only letters, digits, underscores, dashes and dots must be used)
3. whether the project itself exists (Packit creates projects only in its own namespace)
4. whether Packit is allowed to build in your Copr project
5. whether your Copr project/group is not private

[xsuchy]

+1