Refactor layout a little bit

[martonvago]

Description

• This PR renames the "entries" section/folder/page to "how we work". This was already the name of the section on the index page, and I thought having the same name there and in the sidebar made sense. Plus, it's also less vague than "entries".
• I've also removed "onboarding" from the section title on the index page, because to me it looked a bit weird that it was both the title and an item within the section. But this is pretty subjective, so happy to revert.

Closes #146

Testing

• Yes
• No, not needed (give a reason below)
• No, I need help writing them

Tested in the browser.

Reviewer Focus

This PR only needs a quick review.

Checklist

For all PRs that are not general documentation

• Tests accompany or reflect changes to the code
• Tests ran and passed locally
• Ran the linter and formatter
• Build has passed locally
• Relevant documentation has been updated

[lwjohnst86]

I like! Thanks!!