* reader
* record writer
* pkg/output/record_writer_dcf.go
* test/input/test.dcf
* test/cases/io-dcf/
* pkg/cli/option_parse.go
* make fmt
* make dev
* docs and `make dev`
* Auto-unsparsify CSV
* Update unit-test cases
* More unit-test cases
* Key-change handling for CSV output
* Same for TSV, with unit-test and doc updates
* Absent-handling with short-circuiting operators `&&` and `||`
* add a missing file
* artifacts from make dev
* type-errors
* doc content
* artifacts from make dev