Merge branch 'js/trace2-cap-max-output-files'

The trace2 output, when sending them to files in a designated directory, can populate the directory with too many files; a mechanism is introduced to set the maximum number of files and discard further logs when the maximum is reached. * js/trace2-cap-max-output-files: trace2: write discard message to sentinel files trace2: discard new traces if target directory has too many files docs: clarify trace2 version invariants docs: mention trace2 target-dir mode in git-config