add AnnotatedChar support #608

Job	Run time
Documentation	1m 18s
Julia 1.6 - ubuntu-latest - x64 - push	1m 46s
Julia 1.6 - windows-latest - x64 - push	10m 0s
Julia lts - ubuntu-latest - x64 - push	1m 50s
Julia lts - windows-latest - x64 - push	2m 22s
Julia 1 - ubuntu-latest - x64 - push	3m 5s
Julia 1 - windows-latest - x64 - push	3m 35s
Julia pre - ubuntu-latest - x64 - push	3m 32s
Julia pre - windows-latest - x64 - push	4m 24s
Julia nightly - ubuntu-latest - x64 - push	4m 42s
Julia nightly - windows-latest - x64 - push	4m 51s
	41m 25s

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