add flag to skip certain files in the boilerplate header checker

[cpanato]

made a PR in the addlicense project to skip extensions/files and that got merged (google/addlicense#75) see we can use here now :)

This PR adds the -skip flag for certain extensions/files to ignore in the boilerplate header.
for not just the extensions yml/yaml/Gemfile

also, remove the boilerplate for the other yamls files and Gemfile

do we need to add for others?

cc @bobcallaway @lukehinds

[cpanato]

[lukehinds]

Nice!

Couple of noted point, you have a wildcard at the end, will that skip files with no extension? It might be worth adding .md as well, for docs readme etc.

[bobcallaway]

Nice!

Couple of noted point, you have a wildcard at the end, will that skip files with no extension? It might be worth adding .md as well, for docs readme etc.

I think the wildcard means to check all files and directories in $CWD, then applying the skip filter. LGTM

[cpanato]

yes, the star was there in the first repo of sigstore that uses the addlicenses. this is to go over all directories and files from the root where you ran the command.