Update markdown styling rules in the GitHub Action (#1219)

Author: duffh

tools/CI/README_Metadata_StyleCheck/style.rb

@@ -4,4 +4,5 @@
 rule 'MD009', :br_spaces => 2  # Allows an exception for 2 trailing spaces used to insert an explicit line break
 rule 'MD029', :style => :ordered  # Ordered list item prefix is incremental, rather than all ones
 exclude_rule 'MD013'  # Not limiting line length
-exclude_rule 'MD007'  # Not limiting unordered list indentation, tab, 2 or 4 spaces are all fine
+exclude_rule 'MD007'  # Not limiting unordered list indentation, tab, 2 or 4 spaces are all fine
+exclude_rule 'MD034'  # Not using angle brackets around URLs