Fix errors (#11804)

### What problem does this PR solve?

1. typos
2. grammar errors.

### Type of change

- [x] Refactoring

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

common/data_source/html_utils.py

@@ -120,7 +120,7 @@ def format_document_soup(
             # table is standard HTML element
             if e.name == "table":
                 in_table = True
-            # tr is for rows
+            # TR is for rows
             elif e.name == "tr" and in_table:
                 text += "\n"
             # td for data cell, th for header