Add sponsorship links #168

Job	Run time
Internals Bench (ubuntu-latest)	26s
Examples Test (ubuntu-latest, stable)	1m 3s
Internals Bench (macos-latest)	55s
Clippy (ubuntu-latest)	25s
Examples Bench (ubuntu-latest)	2m 33s
Examples Test (ubuntu-latest, nightly)	57s
Clippy (macos-latest)	45s
Examples Bench (macos-latest)	3m 1s
Internals Bench (windows-latest)	1m 2s
Examples Test (macos-latest, stable)	2m 5s
Clippy (windows-latest)	1m 1s
Examples Bench (windows-latest)	4m 35s
Examples Test (macos-latest, nightly)	1m 40s
Rustdoc	17s
Examples Test (windows-latest, stable)	1m 55s
Rustfmt	12s
Examples Test (windows-latest, nightly)	1m 58s
Unit Test (ubuntu-latest, stable)	42s
Unit Test (ubuntu-latest, nightly)	40s
Unit Test (Miri)	1m 13s
Unit Test (macos-latest, stable)	1m 16s
Unit Test (macos-latest, nightly)	1m 48s
Unit Test (windows-latest, stable)	1m 41s
Unit Test (windows-latest, nightly)	1m 9s
	33m 19s

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