Fix footnotes. Again.

src/html.odin

@@ -2,6 +2,7 @@ package main
 
 import "core:fmt"
 import "core:strings"
+import "core:unicode"
 
 escape_html :: proc(s: string, allocator := context.temp_allocator) -> string {
 	b := strings.builder_make(allocator)
@@ -62,8 +63,30 @@ check_only_var_defs :: proc(token: ^Token) -> bool {
 }
 
 slugifyifyifyify :: proc(text: string) -> string {
-	lower := strings.to_lower(text, context.temp_allocator)
-	res, _ := strings.replace_all(lower, " ", "-", context.temp_allocator)
+	b := strings.builder_make(context.temp_allocator)
+
+	for ch in text {
+		lower_ch := unicode.to_lower(ch)
+
+		if unicode.is_letter(lower_ch) || unicode.is_digit(lower_ch) {
+			strings.write_rune(&b, lower_ch)
+		} else if lower_ch == ' ' || lower_ch == '_' || lower_ch == '-' {
+			strings.write_rune(&b, '-')
+		}
+	}
+
+	res := strings.to_string(b)
+
+	for {
+		new_res, replaced := strings.replace_all(res, "--", "-", context.temp_allocator)
+		if !replaced {
+			break
+		}
+		res = new_res
+	}
+
+	res = strings.trim(res, "-")
+
 	return res
 }
 
@@ -91,7 +114,7 @@ print_html :: proc(token: ^Token) {
 		}
 		slug := slugifyifyifyify(strings.to_string(b))
 
-		fmt.printf("<h%d id=\"%s\">", level, slug)
+		fmt.printf("<h%d id=\"%s\">", level, escape_html(slug))
 		for child in token.children {
 			print_html(child)
 		}