keyword_check: scan markdown files too

BUG=b:165908442
TEST=`repo upload` in docs/ scans markdown files too

Change-Id: I3eb6e87b913a181546ac39cdc2f62612d24d75c0
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/repohooks/+/2401364
Tested-by: Mike Frysinger <vapier@chromium.org>
Auto-Submit: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Bernie Thompson <bhthompson@chromium.org>
Commit-Queue: Bernie Thompson <bhthompson@chromium.org>
diff --git a/pre-upload.py b/pre-upload.py
index 7c252ea..2b7567d 100755
--- a/pre-upload.py
+++ b/pre-upload.py
@@ -569,7 +569,7 @@
   """Checks that there is no stray whitespace at source lines end."""
   included, excluded = _parse_common_inclusion_options(options)
   files = _filter_files(_get_affected_files(commit),
-                        included + COMMON_INCLUDED_PATHS,
+                        included + COMMON_INCLUDED_PATHS + ['^.*\.md$'],
                         excluded + COMMON_EXCLUDED_PATHS)
   return _check_lines_in_diff(commit, files,
                               lambda line: line.rstrip() != line,
@@ -632,9 +632,10 @@
 
   keywords = set(common_keywords | set(opts.block))
   keywords = sorted(keywords - unblocked_words)
-  files = _filter_files(_get_affected_files(commit),
-                        opts.include_regex + COMMON_INCLUDED_PATHS,
-                        opts.exclude_regex + COMMON_EXCLUDED_PATHS)
+  files = _filter_files(
+      _get_affected_files(commit),
+      opts.include_regex + COMMON_INCLUDED_PATHS + ['^.*\.md$'],
+      opts.exclude_regex + COMMON_EXCLUDED_PATHS)
   errors = []
 
   def _check_line(line):