Documentation has some great properties as something to work on in early days (so long as you aren't immediately firefighting).
* Documentation always sucks, no-one wants to do it, and everyone knows it has room for improvement. It shows you're willing to roll your sleeves up and do the less glamorous stuff.
* Working on it prompts you to ask simple questions so is a good way to get to know people on the team, and in the process learn the history of the team, why things are the way they are, and where the dark corners are.
* You're immediately creating value, rather than doing bugfixes no-one cares about or having meetings about things which are months away from fruition, and demonstrates you're here to make things better for everyone.
* Documentation always sucks, no-one wants to do it, and everyone knows it has room for improvement. It shows you're willing to roll your sleeves up and do the less glamorous stuff.
* Working on it prompts you to ask simple questions so is a good way to get to know people on the team, and in the process learn the history of the team, why things are the way they are, and where the dark corners are.
* You're immediately creating value, rather than doing bugfixes no-one cares about or having meetings about things which are months away from fruition, and demonstrates you're here to make things better for everyone.