Add Anna to people

We should add an entry for Anna.

@annabecker234 Could you please send me a paragraph about yourself, along the lines of those already up at https://www.phyloref.org/people/? You can also send me your website URL, Github ID, Twitter username and Google Scholar page if you like. I'm not sure we need to include your e-mail address on the website, but I can include that as well if you like!