fix script regex

it was giving some links with errors in the subsection like these:

https://fmhy.pages.dev/storage/#drive-formatting--file_deletion
https://fmhy.pages.dev/storage/#ip--dns_leak_tests

and a bunch more, not replacing every underscore

.github/replace-links-to-fmhy-in-files-in-current-dir.py

@@ -74,7 +74,7 @@ def replace_domain_and_page(text):
     return text
 
 def replace_underscore_in_subsections(text):
-    pattern =  r'(/#[\w]+(?:_[\w]+)*)'
+    pattern =  r'(/#[\w\-]+(?:_[\w]+)*)'
     matches = re.findall(pattern, text)
     for match in matches:
         replacement = match.replace('_', '-')