nvim: Correctly concatenate prose filetypes

Correctly append md_like and org_like into prose filetypes.
And correctly load render_markdown for all md_like filetypes.

NOTE: _Still_ does not work to render for djot on my end. Is it because
of different TS queries? I am not sure.

nvim/.config/nvim/lua/plugins/prose.lua

@@ -1,8 +1,22 @@
+-- append t2 to t1
+-- happens in-place, so it CHANGES t1
+local function concat(t1, t2)
+    local tbl = {}
+	for i = 1, #t1 do
+		tbl[#tbl + 1] = t1[i]
+	end
+	for i = 1, #t2 do
+		tbl[#tbl + 1] = t2[i]
+	end
+	return tbl
+end
+
 local md_like = {
 	"markdown",
 	"djot",
 	"pandoc",
 	"quarto",
+	"rmd",
 	"vimwiki",
 	"codecompanion",
 }
@@ -11,8 +25,6 @@ local org_like = {
 	"org",
 }
 local prose_ft = {
-	unpack(md_like),
-	unpack(org_like),
 	"asciidoc",
 	"bib",
 	"context",
@@ -23,8 +35,9 @@ local prose_ft = {
 	"tex",
 	"text",
 	"typst",
-	"rmd",
 }
+prose_ft = concat(prose_ft, md_like)
+prose_ft = concat(prose_ft, org_like)
 
 local prose_plugs = {
 	-- UI improvements
@@ -100,11 +113,11 @@ local prose_plugs = {
 			},
 		},
 	},
-	-- displays prettier md rendering
 	{
+	    -- displays prettier md rendering
 		"MeanderingProgrammer/render-markdown.nvim",
 		opts = {
-			file_types = { "markdown", "codecompanion" },
+			file_types = md_like,
 			render_modes = { "n", "c", "i" },
 			code = {
 				sign = false,