Additional religions for places of worship symbol rendering

[wmisener]

#910 rendered explicit symbols for eight major world religions, following Carto's choice of religions (and the eight most common specific religion values per taginfo). But it's worth discussing if these should be the only religions rendered explicitly. Beyond changing the symbols for specific denominations (which is currently blocked by OMT, see #927), there are other common religion values both worldwide and in the United States that could conceivably be rendered with unique symbols by Americana. The next most common religion values in the United States include unitarian_universalist (518 place_of_worship) and bahai (79). Other worldwide ones include jain and confucian. Would any of these, or any other religions, be worth rendering with a specific symbol in Americana? If so, what symbols?