rename config.toml to bootstrap.toml

[jyn514]

cargo and bootstrap use the same name for their configuration file. this is confusing. we might want to rename this file so it's easier to understand what's going on.

this will also make it easier to write .gitignore style includes and excludes without mixing up the two types of configs.

@rustbot label A-contributor-roadblock T-bootstrap E-easy E-mentor

[onur-ozkan]

If we do that, if bootstrap.toml don't exist we should fallback to config.toml so we don't break the downstreams.

[Noratrieb]

our docs have also been confused about this before: #127236

[LuuuXXX]

Any progress on this? I'm happy to help.

[onur-ozkan]

Any progress on this? I'm happy to help.

Feel free to claim the task.

[LuuuXXX]

@rustbot claim

[bit-aloo]

@rustbot claim