remove unused code

fsdproject.org/include/footer.lua

@@ -1,13 +0,0 @@
-local footer = {}
-
-footer.render = function(std)
-    return table.concat({
-	std.h2("Other resources"),
-	std.tl({
-		std.external("https://git.vxserver.dev/fSD", "Git Trees"),
-		std.external("https://docs.vxserver.dev", "Documentation"),
-	}),
-})
-end
-
-return footer