completionConfig

Facet for completion configuration.

Scalar settings (activateOnTyping, etc.) are taken from the highest-precedence config, but completion SOURCES (CompletionConfig.override / CompletionConfig.asyncOverride) from EVERY contributing config are merged. This lets independently-registered autocompletion() extensions coexist — e.g. basicSetup's bundled autocompletion() and languageServerSupport's serverCompletion() — instead of the last one silently shadowing the others' sources, which left LSP completion with zero sources (#109).