add .editorconfig file #160

Job	Run time
Compatibility test	5m 0s
Swift 6 Language Mode	0s
Example packages / Linux (5.9)	17m 54s
Example packages / Linux (5.10)	15m 36s
Example packages / Linux (6.0)	17m 12s
Example packages / Linux (nightly-6.0)	27m 55s
Example packages / Linux (nightly-main)	32s
Example packages / Windows (6.0)	4s
Example packages / Windows (nightly-6.0)	2s
Example packages / Windows (nightly-main)	1s
Integration test / Windows (6.0)	2s
Integration test / Windows (nightly-6.0)	1s
Integration test / Linux (5.9)	1m 34s
Integration test / Windows (nightly-main)	1s
Soundness / API breakage check	0s
Soundness / Broken symlinks check	3s
Integration test / Linux (5.10)	1m 37s
Integration test / Linux (6.0)	1m 50s
Soundness / Documentation check	1m 41s
Integration test / Linux (nightly-6.0)	7m 19s
Soundness / Format check	35s
Integration test / Linux (nightly-main)	32s
Soundness / License headers check	4s
Soundness / Shell check	33s
Soundness / Unacceptable language check	2s
Soundness / Python lint check	4s
Soundness / YAML lint check	0s
Unit tests / Unit tests / Linux (5.9)	1m 45s
Unit tests / Unit tests / Linux (5.10)	4m 0s
Unit tests / Unit tests / Linux (6.0)	1m 42s
Unit tests / Unit tests / Linux (nightly-6.0)	2m 6s
Unit tests / Unit tests / Linux (nightly-main)	30s
Unit tests / Unit tests / Windows (6.0)	3s
Unit tests / Unit tests / Windows (nightly-6.0)	1s
Unit tests / Unit tests / Windows (nightly-main)	3s
	1h 50m 24s

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