seems to work, but might need unit tests

tests/weird_headers.md

@@ -0,0 +1,33 @@
+some text.
+
+#### test markdown doc
+
+## header2
+
+#### header4
+
+some text.
+
+```bash
+echo 'hi'
+```
+
+#### another header4
+
+more text.
+
+####third header4
+
+####fourth #header4
+
+ ## this is not a header anymore
+
+##### header5
+
+## a second header2
+
+#### testing
+
+```
+cool code
+```