Rendering en and em dash?

[cprn]

I'm trying to get -- and --- concealed as en (–) and em dash (—). AFAIU I need to use document.conceal.char_patterns, but it doesn't work... I tried this:

    {'MeanderingProgrammer/render-markdown.nvim',
        dependencies = {'nvim-treesitter/nvim-treesitter', 'nvim-tree/nvim-web-devicons'},
        ---@module 'render-markdown'
        ---@type render.md.UserConfig
        opts = {
            completions = {lsp = {enabled = true}},
            heading = {sign = false, width = 'block', left_pad = 1, right_pad = 1},
            document = {
                conceal = {
                    char_patterns = {
                        ['---'] = '—', -- em dash
                        ['--'] = '–',  -- en dash
                    },
                },
            },
        },
    },

...but it returns error, apparently that's not how char_patterns are supposed to look.

The thematic division is rendered correctly, but en dashes remain --:

[edit] I found this project TODO item so it seems it's not supported yet?

If it's planned, I'd strongly suggest implementing all the typical typography:

• quotes: “, ”, ‘, and ’
• dashes: –, —
• ellipsis: …