Add categories.html template to default theme. Fixes #2972

[pauloxnet]

Pull Request Checklist

Resolves: #2972

• Ensured tests pass and (if applicable) updated functional test output
• Conformed to code style guidelines by running appropriate linting tools
• Added tests for changed code
• Updated documentation for changed code

[pauloxnet]

Tests failure seems unrelated to the commit.

[justinmayer]

Hi Paolo. 👋 It seems to me that the test failure is happening because the functional test output was not updated to match the changes in this PR. Did you follow all the steps in the Development section of the docs?

[pauloxnet]

Thanks for the feedback. I'll check it again tomorrow.

[pauloxnet]

@justinmayer thanks again for the feedback. I updated some test to match the fixed categories template. Now all tests pass.

[pauloxnet]

Can some mantainer review and merge or close this PR ?

[justinmayer]

@pauloxnet: Thank you for updating the functional test output.

@getpelican/reviewers: Any final comments on this pull request before it is merged?

[justinmayer]

Many thanks for the enhancement, Paolo! On a side note, for most contributions to Pelican, you can omit filing an issue + PR and instead simply submit a PR by itself. One less thing to keep track of. 😊