Fix admonition header in docs #85

Job	Run time
Documentation	1m 17s
Aqua tests	1m 7s
Julia 1.6 - ubuntu-latest - default	57s
Julia 1 - ubuntu-latest - default	46s
Julia 1.6 - windows-latest - default	10m 19s
Julia 1 - windows-latest - default	1m 14s
Julia 1.6 - macOS-latest - x64	2m 19s
Julia nightly - windows-latest - default	2m 21s
Julia 1 - macos-latest - default	52s
Julia nightly - ubuntu-latest - default	58s
Julia nightly - macos-latest - default	1m 51s
	24m 1s

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