You can join the BookWyrm translation project at translate.joinbookwyrm.com.
Wherever possible, BookWyrm translations should use gender-neutral language. This applies even if a language defaults to male as a neutral gender, or if it uses something similar to "he/she". It's also important for translations to be clear, concise, and legible to a screen reader, and sometimes these goals are in conflict; there isn't a perfect, one-size-fits all answer, and the solution depends on the language.
As a guiding principal, try to place a higher value on inclusive and gender-neutral language than on formal correctness or officially approved style guides. In English, for example, many formal style guides require a singular "she" or "he" pronoun to be used when referring to an individual, but it would be better in BookWyrm to use the gender-neutral singular "they" instead.
If you aren't sure how best to approach a translation problem, comment on the translation or open a discussion topic to address broader-scale questions.
Bookwyrm takes advantage of Django's translation functionality to enable page content to change depending on the user's chosen display language. The Django documentation provides a helpful explanation of how this works, but here is the short version:
{% load i18n %} at the top of your template to enable translations{% trans %}{% blocktrans %} and {% endblocktrans %}. If you are including padding whitespace or line breaks, use trimmed to automatically remove it when the locale file is generated: {% blocktrans trimmed %}<p>{% trans "This list is currently empty" %}</p>
<p>
{% blocktrans trimmed with username=item.user.display_name user_path=item.user.local_path %}
Added by <a href="{{ user_path }}">{{ username }}</a>
{% endblocktrans %}
</p>