Eric Huss d7892f5601 Add optional field for preprocessors ... This adds the `optional` field to the preprocessor configuration to mirror the same option for the `output` table. Missing preprocessors are now an error unless the `optional` field is set. This should help with inadvertently building a book when a missing preprocessor that you expect to be installed.		2025-08-16 13:39:54 -07:00
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gui	Move common lint controls to Cargo.toml	2025-07-23 17:29:12 -07:00
testsuite	Add optional field for preprocessors	2025-08-16 13:39:54 -07:00