Language update

[davelab6]

The following term(s) that should be avoided:

• grandfathered -> legacy

• whitelist -> allowlist

• master -> main

These were found in the following file(s):

nototools/notodiff.py

nototools/data/familyname_and_styles.txt

nototools/noto_lint.py

nototools/unittests/font_tests.py

nototools/shape_diff.py

nototools/update_udhr_samples.py

[nizarsq]

@davelab6 I think this pull request is in the right directory #529